Thanks to a satellite spinning somewhere in outer space, Palestine Liberation Organization leader Yasser Arafat in Jordan and actress Vanessa Redgrave in England had brunch in Washington yesterday.

"I am sorry to say we face some very difficult days," said Arafat, his image huge against a movie screen, about the fate of the PLO after the Israeli invasion of Lebanon. The more than 800 Arab-Americans gathered at the Washington Hilton Hotel for the closing meeting of the American-Arab Anti-Discrimination Committee's annual convention nodded their heads and applauded. "We've had this huge Israeli-American force armed with very sophisticated American arms . . . We faced Israel in the longest Arab-Israeli war -- 88 days! . . . In spite of what we faced, we succeeded in resisting strongly!"

The applause exploded into cheers, but the satellite time was fast slipping away. In Arabic, Arafat made a call for Arab unity. His fingers flashed the peace sign. People stood on chairs and yelled and the big screen went blank.

The video brunch came at the end of a three-day meeting in which panels discussed subjects like "The Israeli Lobby," "Portrayal of Arabs in Cinema," "South Africa and Israel" and "The Unholy Alliance: Right-Wing Evangelicals and the Arab-Israeli Conflict."

Redgrave, her soft quavering voice and intense gaze beamed in from London, spoke against what she called "Zionist imperialism," and "the Zionist press and organizations."

A longtime vocal advocate for the PLO, she asked for help in her court case against the Boston Symphony Orchestra, which canceled a scheduled April 1982 performance of a Stravinsky program she was to narrate after it received threats because of her link with Palestinian groups. Redgrave filed suit against the orchestra, and was awarded $27,500 for her contract and $100,000 in damages, but a judge threw the award out. Her lawyers have now asked a federal appeals court to reinstate the award.

"It not only breached my contract," the actress said of the symphony's cancellation, "but set a precedent for the use of blacklisting for the first time in the United States since the McCarthy era.

"Why was I made an example of? Why did the blacklisting people want to silence me?"

The audience cheered each question and were not silent when she suggested an answer.

"I have stood," she said, "and am pledged to stand in support of the Palestine Liberation Organization."

The first query from the audience was where contributions for the Vanessa Redgrave Defense Fund should be sent.

"She's a heroine to this crowd," said former senator James Abourezk (D-S.D.), chairman of the Anti-Discrimination Committee, after the meal. ADC members lined up to shake his hand and hand him checks that were, they said, "for Vanessa."

By then, folk singer Pete Seeger was racing off the stage on his way to the Takoma Park Folk Festival. A friend of Abourezk, Seeger stopped by the Hilton to sing one song in Arabic and one in English. The audience attempted to clap along to the Arabic song, but faint sounds of occasional laughter suggested Seeger's rendition was a bit less than polished. When he finished, however, he, like everyone else, received wildly enthusiastic applause.

The largest Arab-American grass roots organization, ADC was founded five years ago to combat unfavorable stereotypes of Arabs and influence American policy toward the Middle East. This year, ADC ran a national ad campaign on what Abourezk called in his keynote address "the $14 million a day that the Congress is stuffing in the pockets of the Israelis."

"With the one exception of the TWA hijacking, I think that things have improved vastly," said Abourezk yesterday about American attitudes toward Arabs since ADC was founded.

"A lot of racism came to the surface at that time. People blamed anyone who was an Arab for that incident, which was ridiculous. But I think that has passed."

The hijacking of the TWA jet and its passengers last June evoked another response from Halim Awde, executive director of the Boston chapter of ADC.

"Our problem is when something happens, we do not go to the cause of what happened," he said. "Something happened that caused this violence -- we all deplored the violence, ADC and other groups. But how many Americans knew there were 750 Lebanese in Israeli jails, held with no charge against them? You don't change your child until he cries -- I am sorry, but it is true. We're sorry it happened that way, but it happened.

"The fact that one American went to a McDonald's with a gun and killed 20 people -- can you call all Americans terrorists?"