What was going on when I was born?

Mary L. Balestra, a 33-year-old working mother of three who lives in Pelham, N.Y., is aware of Philip Morris Inc.'s recent agreement to buy the General Foods Corporation. She also knows that the nearly $5.8 billion deal is only the latest of many takeovers that have occurred in the food industry in recent years. Is she concerned that this acquisition binge may affect her choices at the supermarket and the prices she has to pay for food? ''Nope,'' said Mrs. Balestra. ''As a consumer, it's not going to affect me. If Philip Morris takes over General Foods and Jell-O goes up a nickel, I'll just buy Royal Pudding or a store brand. I don't care about the takeovers.

The Administration virtually gave up hope today of seizing a Palestinian guerrilla leader who fled to Yugoslavia from Rome as the United States sought to extradite him for planning the hijacking of an Italian cruise ship. Administration officials said they expected the Yugoslav Government to announce formally Monday that it would neither hold nor extradite the Palestinian, Mohammed Abbas. The United States was given that message informally today in Belgrade, Justice Department officials said. As officials awaited the formal Yugoslav response, the White House and State Department considered diplomatic moves against the Italian Government for not arresting the Palestinian. The White House called Mr. Abbas, who is known as Abul Abbas, ''one of the most notorious Palestinian terrorists,'' and said he ''has been involved in savage attacks on civilians.''

The first shock of the evening came two hours before game time tonight when the St. Louis Cardinals lost their base-stealing champion, Vince Coleman, in a bizarre accident: His left leg was trapped and bruised under a 1,200-pound tarpaulin cylinder before the fourth game of the National League playoff. But, having lost the leadoff man on their relay team, the rookie who stole 110 bases this season, the Cardinals went out and provided a shock of their own. They sent 14 men to bat in the second inning, scored a record total of nine runs on eight hits and two walks and overwhelmed the Los Angeles Dodgers, 12-2. As a result, the Cardinals won their second straight game and tied the playoff at two games apiece. They will shoot for the lead Monday afternoon, with Bob Forsch pitching against Fernando Valenzuela of the Dodgers, but Coleman will not return to the lineup until Game 6, when the series is resumed Wednesday in Los Angeles.

The nation's airline industry, which has struggled to adapt to deregulation for six years, has entered a new phase by turning to quick growth through acquisition. In the past several weeks, Piedmont Aviation Inc., a fast-growing carrier in the East, has forged an agreement to acquire Empire Airlines, a large regional carrier based in Syracuse. Last week, People Express Airlines, which has expanded at a torrid pace, worked out an agreement to acquire the Denver-based Frontier Airlines. If the deal goes through, it would catapult the upstart, low-fare airline from its position as the nation's 12th-largest carrier to the No. 5 spot. In addition, Elizabeth Hanford Dole, the Secretary of Transportation, decided in a preliminary ruling last week to allow United Airlines to acquire the Pacific routes of Pan American World Airways, although United may be required to give up its current gateway serving Seattle and Portland.

A year ago, Salvadoran leftist guerrillas and President Jose Napoleon Duarte met for the first time in the mountain village of La Palma and raised the hopes of their countrymen that peace might come after five years of civil war. Those hopes may have been impossibly high, but their loss today is palpable and has even reached into Mr. Duarte's home. The President, who walked unarmed into the heart of a war zone to meet the guerrillas, is now imploring them to release his kidnapped daughter. Conversations with dozens of Salvadorans from all classes of society give the strong impression that exhaustion is gaining hold in a country that has joined Northern Ireland and Lebanon as a land in which violence is normal. Resignation, cynicism and a simple hunger to survive have replaced the fragile faith that many placed in Mr. Duarte and the rebels' promise to try to stop fighting 12 months ago.

An Associated Press dispatch from Santa Ana, Calif., in some copies yesterday on the investigation of a fatal bombing misstated the name of the group whose office was bombed. It was the American Arab Anti-Discrimination Committee.

Hostages and Hijackers Efforts to extradite a Palestinian for planning the seizure of the Achille Lauro were virtually given up by the Reagan Administration. The Palestinian guerrilla leader, Mohammed Abbas, fled to Yugoslavia from Rome on Saturday. Administration officials said they expected Yugoslavia to confirm formally Monday that it would not hold the Palestinian in custody, nor would it extradite him. This information was given informally to the United States, Justice Department officials said. [Page A1, Column 6.] Italy's release of a Palestinian against Washington's express wish was being explained by the Government of Prime Minister Bettino Craxi as necessary to avert a collapse of its ties with the Arab world. There were strong indications that Italy feared a sharp outburst of Palestinian terrorism if it had handed over Mohammed Abbas, leader of a faction of the Palestine Liberation Front, to the United States. [A1:5.]

Companies Forstmann Little raised its offer for Revlon to $57.25 a share, or $1.62 billion. And, in an unexpected move, Revlon's chairman said he no longer planned to invest in the leverged buyout deal. The new offer tops, by $1 a share, an offer by Pantry Pride. [Page D1.]

A new skirmish has broken out between the Russians and the Chinese. This time, however, the fight is over food, and the battle front is slightly to the left - and right - of Carnegie Hall. For nearly half a century, the only tea room in the area was the Russian Tea Room, a bit of turn-of-the-century St. Petersburg on West 57th Street. But two months ago, the old Carnegie Tavern, a block away, quietly succumbed to changing tastes and gave way to a new establishment. It calls itself the Chinese Tea Room. What has since developed is New York's own version of the Sino-Soviet feud, with Carnegie Hall, like the Amur River, serving as the border between the warring parties. The Russian Tea Room, contending that customers will confuse the two restaurants or think they are under common ownership, has demanded that the Chinese Tea Room drop the name, which its owner has refused to do.

Reagan Administration officials said today that they had transcripts of radio conversations that took place during the hijacking of an Italian cruise ship between the hijackers and a Palestinian guerrilla leader who was later freed by the Italian Government. According to American sources, transcripts of conversations between the hijackers and the guerrilla leader, Mohammed Abbas, were provided to the Italian Government. The sources said Italy was given evidence showing that Mr. Abbas remained close to the ship and directed the hijacking. Nevertheless, Italian officials allowed Mr. Abbas to leave Italy and fly to Yugoslavia this weekend.

The Government of Prime Minister Bettino Craxi struggled today to limit the damage to its relationship with the United States by portraying its decision to release a Palestinian leader, against Washington's wishes, as necessary to avert a collapse of its ties with the Arab world. There were strong indications that Italy feared a sharp outburst of Palestinian terrorism if it had handed over Mohammed Abbas, head of a faction of the Palestine Liberation Front, to the United States. The United States Ambassador, Maxwell M. Rabb, met with Foreign Minister Giulio Andreotti for more than two hours today. Emerging from the meeting, he said he had repeated the Reagan Administration's contention that the release of Mr. Abbas, also known as Abul Abbas, was ''incomprensible to the United States.''

The Reagan Administration plans to ask Congress for the legal authority to expand greatly the Government's use of confidential tax data and give Federal agencies direct access to information about the private insurance coverage of anyone in the United States. Under the proposal, the tax information would be used by the Government to determine the eligibility of millions of people applying for such widely used Federal programs as guaranteed student loans and veterans' insurance. The access to private insurance records would allow Federal agencies to make sure an individual was not eligible for privately financed insurance benefits before it paid a claim under such Government programs as Medicare. Congress Expected to Get Bill The Government does not now have the legal authority either to use tax information for such purposes or to gain access to private insurance files.