What was going on when I was born?

Dr. Elliot M. Gross, whose conduct as the New York City Chief Medical Examiner has been the subject of city and state inquiries for almost a year, was returned to office yesterday by Mayor Koch. The Mayor's decision means that Dr. Gross, who has been on his second paid leave of absence for nearly five months, is again the city administration's top pathologist. He will remain so, the Mayor said, unless he is found guilty of charges by the State Health Department of gross negligence or incompetence. The Mayor acted less than a week after the State Health Commissioner had recommended that the charges -set aside on procedural grounds by an administrative law judge - be reinstated and judged on their merits. 'Time Has Come' ''He's been through the fires of hell,'' Mr. Koch said of Dr. Gross at a City Hall news conference that had been scheduled with little notice. ''How long do you keep the guy roasting?''

Congress today approved two measures that together form the most sweeping alteration in Government farm policy since the Depression. The first bill would reduce Government income and price supports to farmers for the first time since the program was established in 1933. The second would reorganize the nation's farm credit system and bolster it by allowing tens of thousands of farm foreclosures. Together the measures provide a framework for agriculture, the nation's largest industrial sector, for the rest of the decade.

The State Senate's Republican leadership today proposed a broad tax-cut plan that it said would save taxpayers $3.9 billion over five years. The plan would eliminate the state sales tax on articles of clothing sold for under $75. It would increase the state income tax's individual personal exemption - now at $900 - to $1,000 for an adult and $1,200 for each dependent child. The program would also allow both homeowners and renters to receive a credit against their state income tax for a portion of school property taxes. It would reduce corporate income taxes, particularly for small businesses, and taxes for retired people whose main source of income is from investments.

As the holiday shopping pace intensified this week, curious throngs gathered outside the sparkling 34th Street tower that is Herald Center. They watched as clowns juggled, a break dancer cavorted and a young woman blew bubbles in the front window of the city's first vertical shopping center devoted exclusively to retailing. However, few in the sidewalk audience seemed to head inside to shop. Herald Center opened eight months ago in the heart of Manhattan's central shopping district to a surge of visitors eager to see the top-scale stores and trendy restaurants. Among the stores they found were Ann Taylor, Brookstone, Caswell-Massey, Alfred Dunhill of London and Furs by Peter Thomas, but they also discovered that only about half the center was occupied.

The former head of fund raising for the American Cancer Society's New York City branch was indicted yesterday for masterminding a scheme that enabled contributors to take nearly $4 million in illegal tax deductions. Federal officials said contributors made out checks to the Cancer Society and then received cash kickbacks for 90 percent of the amount of the checks. The contributors could deduct the full amounts on their income-tax returns, using the canceled checks to back their claims. The indictment, by a Federal grand jury, was announced by Rudolph W. Giuliani, the United States Attorney in Manhattan.

The City of London, Britain's Wall Street, has been buffeted recently by a series of been buffeted recently by a series of fraud cases, tarnishing the reputation of Europe's leading money center and putting pressure on the Government to strengthen the policing of London's financial district. In the halls of Parliament and in the British press, the City of London has become a major political issue for the first time in more than a decade. To help deal with the problem, the Government is scheduled to disclose on Thursday its Financial Services Bill, which is expected to be the most sweeping piece of regulatory legislation governing the City in a generation. And the British Treasury on Tuesday issued a white paper with recommendations for tighter banking supervision, under the direction of the Bank of England. According to the Government report, the stiffer controls, including a new supervisory body, are to be included in a new banking bill ''at the earliest possible opportunity.''

President Reagan, pledging to maintain the nation's military buildup, said today that balancing the Federal budget by 1991 would require deep cutbacks of what he called ''wasteful and unnecessary'' domestic programs. In his first detailed statement on the far-reaching budget measure that he signed last week, Mr. Reagan made it clear that he would seek to apply the brunt of the proposed restraints to domestic programs. Mr. Reagan's proposed budget for the 1987 fiscal year, which begins next October, will be sent to Congress early in February. Aides said Mr. Reagan was especially uneasy that the new law, demanding five years of steady deficit reductions, was being viewed as compelling him to restrain military spending. Further Speeches Are Planned Mr. Reagan's comments today, the aides said, to be followed by further speeches in the next two months on the budget, were designed to affirm his commitment to a military buildup and to lay the groundwork for far-reaching efforts to reduce domestic programs.

A movie review of ''The Color Purple'' yesterday gave the film's rating incorrectly. It is PG-13.

The shares of the Union Carbide Corporation and the GAF Corporation rose sharply today amid widespread rumors that GAF was preparing to increase its $68-a-share tender offer for Carbide. A higher bid by GAF had been expected by many analysts, since Carbide shares, buoyed partly by the company's own plan to repurchase 35 percent of its stock, had been rising since Monday. In trading on the New York Stock Exchange today, Carbide shares rose $1.75, to $72.75, $4 more than GAF's $68-a-share cash bid. GAF shares closed at $62.875, up $4.50.

Apple Computer Inc., in an announcement that surprised Wall Street, said today that it expects record earnings in the current quarter, despite a drop in revenues. Apple said it expects net income for its first fiscal quarter, which ends Dec. 27, to be about $52 million, or 85 cents a share, up 13 percent from $46 million, or 75 cents a share, in the quarter a year ago. Analysts had been expecting earnings this quarter of about 50 cents to 60 cents a share, so the announcement sent Apple stock soaring in heavy trading. Apple, traded over the counter, closed at $22.125, up $1.50 a share, with almost 2.5 million shares changing hands.

New Yorkers pay more for what they eat and where they live and work because of organized crime's grip on legitimate businesses, law-enforcement officials said yesterday. Precisely how much more is hard to quantify, they acknowledged. However, one economist estimated that the Mafia's penetration of the construction, delivery, food and private garbage collection unions and industries, among others, costs consumers hundreds of millions of dollars each year in New York City alone. This is apart from the financial and social consequences of white-collar crime in general and of such illegal activities as gambling and narcotics trafficking. Search for Killers Among the crime organizations said to have infiltrated the food and carting industries is the Gambino family, whose reputed leader, Paul C. Castellano, was gunned down Monday night outside a Manhattan restaurant. The search for his killers now involves about 50 police detectives and Federal Bureau of Investigation agents, but officials said yesterday that they lacked strong leads. [Page B11.] Many officials say the cost that organized crime imposes on legitimate businesses has driven some companies from the city and is partly responsible for the decline of the Port of New York.

Administration officials said today that they expected the Senate to approve a tax-revision measure next year with greater incentives for business investment than those contained in the bill approved Tuesday night by the House of Representatives. However, Senator Bob Packwood of Oregon, the Republican chairman of the Finance Committee, said the Senate bill would not differ much from the version passed by the House. In the aftermath of the House approval of the most comprehensive changes in the tax law since World War II, President Reagan said, ''America could feel almost that true tax reform is in its grasp.'' 'All Deliberate Speed' Urged The President indicated that House passage should dispel any notions that he was a lame duck and added, ''We must move forward from here with all deliberate speed to pass a tax reform bill that will spur economic growth, create jobs and give American families the long overdue tax relief that they deserve.'' In an interview, Treasury Secretary James A. Baker 3d said his main goal in the Senate would be to ''improve significantly'' the treatment of ''depreciation, capital formation and investment incentives.''