One former actor played to another at the White House last night, speaking from the glossy political stage that has become a mark of the current presidency. The Reagans had Egyptian President Anwar Sadat and 100 others over for an official dinner, and in his toast, Sadat was blunt:

"You can help this process of reconciliation, Mr. President, by holding a dialogue with the Palestinians through their representatives," Sadat said. "It would be an act of statesmanship and vision."

"This does not mean an alteration in our position," Reagan replied in remarks to a reporter after dinner. He was previously referred to the PLO as a "terrorist" organization.

So, will Reagan talk to the PLO?

"I would hesitate to answer here what our diplomatic course would be," the president replied carefully. "The answer is we're going to do everything we can to bring about peace in the Middle East."

Both Reagan and Sadat are former actors, although Sadat had a mere teen-age fling with the stage. They're also both men from poor rural towns who transformed themselves from political long shots into presidents.

Last night the White House state rooms were filled with the filmy gowns and glinting jewels that make White House dinners heady occasions for even the most jaded Washington presence. Stuffed into the Blue Room were the president, Vice President George Bush, Secretary of State Alexander Haig, Sadat and assorted other politically beautiful people to round out the scenery. The perfumes and smell of the flowers mixed with the low lights, which gave the women milky complexions for at least one-night.

"Everything's so soigne ," said an utterly serious C.Z. Guest, the New York socialite. "All the flowers, the plants, the perfect taste. "I'll tell my friends when I go back to Saratoga that I sat between Roger Moore and Mr. [Michael K.] Deaver. They won't believe it. I mean, they run the world, don't they? They won't believe it. We're going back at the crack of dawn. We have a horse racing tomorrow."

The White House dinner was the end of the first day of Sadat's visit here, a day in which he asked Reagan first off about establishing contact with the PLO. Perhaps more important, Sadat also wants to establish the same rapport with Reagan that he had with Jimmy Carter -- rapport he feels is essential for receiving the economic and military aid he needs from the United States.

The evening began in a muggy haze. The First Host and Hostess stepped lightly onto the red carpet of the North Portico entrance, holding hands and laughing between themselves. You had to read lips to figure out what they were saying.

Nancy Reagan wore a white Nippon dress with puffed sleeves and a full skirt, vaguely suggesting the romantic look that was the rage during her recent trip to London. Her hair was pouffier and suspiciously Monsieur Marc-like. He's the main competitor to hairdresser Julius, who has a White House pass.

The Sadats arrived about 7:30 p.m. "Nice to see you," Reagan said. You couldn't hear what Sadat said. Everybody looked stiffly pleasant, just as at the beginning of any big party.

The four stopped for pictures. Reagan and Sadat had the most natural smiles. Jeham Sadat had an unrelenting gaze, while Nancy Reagan at first assumed her wide-eyed look but then remembered to grin.

Then in they went. They were followed by Sadat's entourage, a mass of men in seemingly identical dark suits with threatening briefcases.

Once inside, the guests were warming up. It was the usual mix of politicians, foreign dignitaries, business moguls, Hollywood types and simple rich people.There was only a little exotica, this time in the form of Moore, alias James Bond. The Reagans saw "For Your Eyes Only" at Camp David. They're big fans.

"We just like him -- and his wife," said Nancy Reagan after she'd danced at least three times. But reporters didn't know that earlier.

"WHY WERE YOU INVITED?" an uncouth news hound asked as Moore was arriving at the White House.

"Maybe because I filmed in Egypt," he offered politely. A pause. "And I'm very good on a camel." He was deeply tan.

Sadat's 19-year-old daughter, Jihan Osman, wasn't there. She became ill after her flight from London, and is expected to be hospitalized at George Washington University Hospital for a day or two.

Other entries from the guest list:

John and Bonnie Swearingen of Standard Oil of Indiana, who danced to "Sleepy Time Gal" for the First Couple after the First Couple danced with each other. (John Swearingen, of all things, cut in on the president.) Robert Stack, the actor. Formerly secretary of state Henry Kissinger, who said he didn't miss the place. ("I think everybody ought to get his chance at a nervous breakdown. I had mine eight years.") Walter Wriston of Citicorp. Budget director David Stockman, who came with his girlfriend, Jennifer Blei.

"Talk to Jennifer," he told reporters who asked him questions about Sadat. "She has something more interesting to say." But no luck there, either.

Others at the White House included Mary Lasker, the major patron of the arts and liberal causes; James Cheek, president of Howard University; and Judy Woodruff of NBC, who came with her husband, Al Hunt, who works for The Wall Street Journal.

"When are you going to have your baby?" another uncouth reporter called to the pregnant Woodruff.

"I'll have a press availability later," said her husband, chuckling.

For dinner, guest ate cold salmon, squab, wild rice, green beans, bibb lettuce salad, cheese and peach mousse. ythen there was entertainment from duo pianists Arthur Gold and Robert Fizdale. And finally, dancing in the flower-filled Great Hall.

About 11:30 p.m. the Reagans left their guests, Nancy Reagan pulling along the president as they went upstairs to bed.

The following guests were invited to last night's White House dinner given by President and Mrs. Reagan for Egyptian President Anwar Sadat and Mrs. Sadat . Gen. Kamal Hassan Ali, deputy prime minister and minister of foriegn affairs Dr. Abdel Razack Abdel Meguid, deputy prime minister for economic and financial affairs Lt. Gen. Mohamed Abdel Hallm Abu Ghazala, minister of defense and war production Dr. Mamdouh Kamal Gabr, minister of state for health Mansour Mohamed Hassan, minister of state for culture and information Ambassador of the Arab Republic of Egypt Ghorbal, and Mrs. Ghorbal Dr. Ahmed Esmat Abdel Meguid, permanent representative of the Arab Republic of Egypt to the United Nations, and Mrs. Meguid Fawzy Abdel Hafez, private secretary to the president Osama El Baz, first foreign undersecretary Dr. Mohamed Atteya, medical advisor to the president Abdel Khalek Abdel Ghaffer, daughter of President Sadat, and Mr. Ghaffer Richard V. Allen, assistant to the president for national security affairs, and Mrs. Allen Leonore Annenberg, chief of profocol, and Walter H. Annenberg Rep. Bill Archer (R-Texas) Alfred Atherton Jr., American ambassador to the Arab Republic of Egypt, and Mrs. Atherton Sen. Howard H. Baker Jr. (R-Tenn.), and Mrs. Baker James A. Baker III, chief of staff and assistant to the president, and Mrs. Baker Jacques Bergerac, president, Balmain Perfumes inc., and Mrs. Bergerac, Paris Jennifer Blel J. Carter Brown, director, National Gallery of Art, and Mrs. Brown Vice President and Mrs. Bush Willard C. Butcher, chairman, Chase Manhattan Bank, and Mrs. Butcher, New York Dr. James E. Cheek, president, Howard University, and Mrs. Cheek Mr. and Mrs. Charles A. Dane Jr., New York Michael K. Deaver, deputy chief of staff and assistant to the president Rep. John J. Duncan (R-Tenn.) Robert Fitzdale, pianist, Walter Mill, N.Y. Arthur Gold, pianist, Water Mill, N.Y. Rep. Willis D. Gradison Jr. (R-Ohio), and Mrs. Gradison Mr. and Mrs. Winston F. C. Guest Jr., New York Alexander M. Haig Jr., secretary of state Rep. Kent Hance (D-Texas), and Mrs. Hance Albert R. Hunt, Wall Street Journal; Mrs. Judy Woodruff Hunt, NBC Sen. Robert W. Kasten Jr. (R-Wisc.) Mr. and Mrs. Tom Kempner, New York Mr. and Mrs. Henry A. Kissinger Mrs. Albert Lasker, New York Mrs. Noha El Sadat Marel, daughter of President Sadat Mrs. Peter McCoy, wife of the deputy assistant to the president and director of staff for the first lady Edwin Meese III, counselor to the president, and Mrs. Meese Mr. and Mrs. Roger Moore, Los Angeles Mr. Edmund Morris, writer, and Mrs. Morris, New York Sen. William V. Roth Jr. (R-Del.) Dr. Howard A. Rusk, chairman, Institute of Rehabilitation Medicine, New York Gamal Sadat, son of President Sadat, and Mrs. Sadat Mr. and Mrs. Henry Salvatori, Los Angeles Omar Sharif, London Mr. and Mrs. Earl Smith, Palm Beach, Fla. Mr. and Mrs. Robert Stack, Los Angeles David Stockman, director, Office of Management and Budget John Swearingen, chairman, Standard Oil Company of Indiana, and Mrs. Swearingen, Chicago Nicholas Vellotes, assistant secretary of state for Near Eastern and South Asian affairs, and Mrs. Vellotes Helene von Damm, special assistant to the president Rawleigh Warner Jr., chairman, Mobil Oil Corp., and Mrs. Warner, New York Caspar W. Weinberger, secretary of defense Walter B. Wriston, chairman, Citicorp, New York Robin Hancock Barbara Haig Dr. Geoffrey Kemp, National Security Council staff member Ambassador Shafel Abdel Hamid, chairman of the State information Agency Charles Z. Wick, director, international Communication Agency Rep. Barber B. Conable Jr. (R-New York), and Mrs. Conable Richard G. Darman, deputy assistant to the president and deputy to the chief of staff, and Mrs. Darman