What was going on when I was born?

Guerrillas killed at least 46 people, including 39 Philippine soldiers, in an ambush of an army patrol unit northwest of here last week, a high military officer said here today. The officer, Maj. Gen. Delfino Castro, head of the Philippine Army's Southern Command, said the death toll was the highest suffered by Government forces in a single attack since the leftist rebels began operating on a major scale 10 years ago. Seven civilians, including a woman and child, were among the victims. General Castro said, in an interview, that the ambush, which occurred on Thursday, had been carried out by about 70 guerrillas belonging to the New People's Army, the military arm of the Philippine Communist Party.

America needs a comprehensive industrial policy to rebuild the economy, bring about balanced economic growth and strengthen the nation's international economic position, A.F.L.-C.I.O. leaders said today. The executive council of the 13.8 million-member American Federation of Labor and Congress of Industrial Organizations also called for the creation of a Re-industrialization Board made up of representatives of labor, business and government, to guide the revival of industrial institutions the federation said was necessary. A National Development Bank, whose activities would be directed by the board, would be part of the new industrial policy. It would be created to invest private and public funds in what the council described as ''necessary re- industrialization projects.''

Because of an editing error, a wire- service article in some editions of Sunday's sports section incorrectly identified the manager of the Kansas City Royals. He is Dick Howser.

In the chilly expanse of the Pacific Ocean off Alaska's southern coast, the offshore oil rig Ocean Odyssey is being towed away this week. The rig has been leased since April by the Atlantic Richfield Company to explore the Gulf of Alaska. Arco has spent $43 million on this well, a single hole extending 18,500 feet into the earth's crust. But two weeks ago, the company concluded that the well was dry. ''You have winners and losers in oil exploration,'' said William F. Kieschnick, Arco's president and chief executive officer. ''And we intend to press ahead.''

In a decision that is expected to impede investigations by the Securities and Exchange Commission, a Federal court has refused to review two rulings that impose stringent new procedures for the commission to follow before questioning witnesses. The rulings were issued earlier this year by two separate three-judge panels of the United States Court of Apeals for the Ninth Circuit, based in San Francisco. The panels held that the commission must give advance notice to each subject of an investigation before it could serve subpoenas on other individuals or companies who might aid in the inquiry. Late Friday, the Court of Appeals for the Ninth Circuit refused a motion by the S.E.C. to rehear the rulings before the entire court. In addition to California, the Ninth Circuit serves Alaska, Arizona, Hawaii, Idaho, Montana, Nevada, Oregon and Washington State.

After more than a decade of delay in efforts to amend key aspects of Federal criminal law, Congress is working toward passing several measures that could have a major effect on the way defendants are prosecuted and sentenced in the Federal courts. The Reagan Administration is strongly backing the legislation and has participated in an unusual bipartisan agreement in the Senate that seems to guarantee speedy passage of many of the proposals there. In the House, the situation is far more complicated, although Representative Peter W. Rodino Jr., the New Jersey Democrat who is chairman of the Judiciary Committee, says some action will occur there, too, although perhaps not until next year. Would Eliminate Parole Among the proposed changes are these: - Uniform sentencing and the elimination of parole.

The Economy Capital outlays for new plants are lagging, while consumer spending has been surging. But many economists believe that the decline in spending by businesses has ended and that substantial growth will begin soon. (Page D1.)

The New York City Transit Authority - with the help of three French engineers, a handful of retired track supervisors and the guidance of its acting president - has in the last month accelerated its effort to get the city's subways rolling on time. The number of red tags on the tracks, which indicate rail problems, has been whittled down and the on-time performance of the system has climbed, according to Transit Authority figures. The track problem was underscored last evening when a northbound IRT No. 1 train derailed as it left the station at 137th Street and Broadway, which is not a red-tag area. No injuries were reported. It was the 14th subway derailment this year.

Opening night was a blur of handshakes and congratulations. Bunches of flowers arrived at the side door all day long until even the cigarette machine downstairs wore a palm tree and a basket of wildflowers. In brand-new suits, Pat Rogers and Bob Barbero made the rounds of the dining room asking over and over, ''Is everything O.K.?'' It had taken them nine months to open Rogers and Barbero, the newest business on the Eighth Avenue block between 17th and 18th Streets, in the Chelsea section. In that time, they had transformed what used to be a pawn shop into a restaurant, covering the crumbling black-brick facade with pale beige stucco, rebuilding the floors and the walls, spending nearly $350,000, most of it borrowed.

CORRECTIONS An article in Business Day Saturday on stock market trading attributed the earnings goal for the Texas Oil and Gas Corporation to the wrong year. The goal, a 15 percent increase, is for the year ending Aug. 31, 1984. For the year ended Aug. 31, 1983, according to the company's preliminary figures, earnings rose 20 percent.

Two weeks ago at the Waldorf-Astoria Hotel, Roger B. Smith, chairman of the General Motors Corporation, painted a rosy picture of the nation's economic prospects. With lots of hard work and a bit of luck, he told the annual Business Outlook Conference, there was a good chance for five years of solid expansion in the nation's economy. But even as Mr. Smith was speaking, the director of corporate planning for a major capital goods company based in the Middle West could be seen shaking his head in disbelief. This vignette tells a lot about what has been going on in the American economy this year. Consumer spending - especially for autos and housing - has come roaring back to life. But expenditures on new plant and equipment, which represent the business investment side of the economy, have barely started to recover.

Manhattanville College has decided that smaller is beautiful. Enrollment at the small liberal arts college in Purchase, N.Y., has been steady in recent years, but Barbara Debs, the president, has been studying census data showing a dearth of high school graduates in the years to come. As a result, Manhattanville plans to reduce the size of its student body from 900 to 830 by 1987. ''Most small colleges and a lot of big ones now have a choice,'' said Mrs. Debs. ''You can get slightly smaller and maintain quality, or you can keep the numbers up and lower your standards. We've decided to maintain quality.''