President Valery Giscard d'Estaing of France went to the airport today to pick up Egyptian President Anwar Sadat and bring him home for a family lunch intended to put an end to two years of frosty relations, ever since Egypt signed the Camp David peace accords with Israel.

The Franco-Egyptian rappochement was loaded with special protocol touches by Giscard, who gave the Egyptian leader and his wife the French government guest house for state visitors and full military honors even though Sadat is officially here on a "private visit."

The thaw with the only Arab leader who has achieved popularity among world Jewry comes as Giscard prepares for a close reelection campaign in which French Jews are being heavily solicited to organize for the first time into a monolithic Jewish vote to punish Giscard for his government's policies condemned by Israel as pro-Arab. Most political insiders here believe that, after initial resistance, the effort to organize a Jewish vote has been succeeding.

From Sadat's viewpoint, a rapprochement with France is understood to have the advantage of neutralizing the leader in the 10-member European Community's drive to replace the Camp David negotiations on Palestinian autonomy with an attempt at an overall Middle East peace settlement including a solution to the Palestinian problem.

By coming to Western Europe and telling the Europeans, as he did yesterday in a widely publicized speech in Luxembourg to the European Parliament, that European initiatives on the Middle East are actually welcome, Sadat does not only apparently hope to deflect them in a direction that is more constructive from his standpoint. He also is reliably said to be deliberately encouraging the Europeans to help him fill the potentially dangerous void in Middle East diplomacy between now and the Israeli election in June when giving the new U.S. administration the time it needs to formulate a policy for the region.

Sadat's move gives France an opportunity to appear to be in the thick of Middle East developments just as French diplomats are expressing anxiety over a project of the British foreign secretary, Lord Carrington. He is expected to try to take over from France the lead European position on the Middle East when he assumes the rotating chairmanship of the European Community for six months starting July 1, they say.

Egypt and France have business to do over the challenge to their mutual interests in Africa by the Libyan leader, Col. Musmmar Quddafi. Elysee Palace sources said that in addition to the Middle East, Sadat and Giscard concentrated in a postluncheon talk of more than two hours on the situation in Chad, the former French colony with which Libya recently announced a merger backed up by Libyan tanks and planes that spelled victory for the winning side in the Chadian civil war.

The French have already demonstrated their willingness to cooperate military with Egypt by recently sending a high-level military mission to Sudan, Egypt's major ally against Libya. That visit was immediately followed by a trip to Sudan by French Defense Minister Robert Galley. The French minister is thought to have been the singer of a Franco-Sudanese technical military assistance pact that reliable sources report was signed last month. It is said to have been in the works for a year but to have been accelerated by the Libyan actions in Chad.

Libya's victory turned Sudan, with its long, virtually undefended border with Chad, into the most likely next target for Quaddafi. Egypt supplied the losing side in Chad via Sudan. If Libya ever managed to topple the basically fragile Sudanese government, which took years to achieye a negotiated settlement of its own north-south civil war, Egypt would have to deal with a hostile southern frontier as well as the present discomfort of having the openly inimical Quaddafi on its western border.

The French are understood to be preparing to provide arms to Khartoum, to train Sudanese officers in France and to send military technicians to Sudan. In November, France and Egypt initialed a deal for an Egyptian purchase of about 30 Franco-German Alpha-Jet training and ground support planes. France passed last year into second position behind the United States as aid-giver to Egypt with more than $250 million in loans at giveaway interest rates.