Thousands of Jews gathered on the Ellipse under a sunny sky yesterday to sing, dance, eat kosher foods and reminisce at an annual festival sponsored by the United Jewish Appeal Federation of Greater Washington.

The six-hour celebration, which included a 10-kilometer walkathon, raised at least $73,000 to benefit the organization's social and humanitarian projects here and around the world, including first-aid efforts in Israel.

But for many the event was social -- a chance to see longtime friends and celebrate the sights and sounds of Israeli and Jewish life. Organizers estimated that between 18,000 and 20,000 people attended the festival.

"It's kind of a recharging of batteries," said John Hornstein, 43, a physicist at the Naval Research Laboratory.

"We were here last year, and I felt the same way."

"It's the largest single event that the Jewish community has," said Joel Breslau, the UJA Federation president.

"It's our ethnic moment of the year."

"I feel at home here," said Debra Wasserman, 27, a cookbook author. "I grew up in Long Island, in an area that is 90 percent Jewish. Everyone here today looks like someone I know."

Featured at the festival was an Israeli-style "shuk," or marketplace, where people could sign a petition calling for the release of Soviet dissident physicist Andrei Sakharov or get the latest information on Habonim Dror -- "The Groovy Kibbutz Youth Movement."

The B'nai B'rith was represented, as was the Board of Jewish Education, the Jewish Community Council, the Jewish Council for the Aging and the Washington Association for Ethiopian Jews.

Local artists congregated at the shuk, too, demonstrating weaving and other skills and selling ceramic menorahs, hand-painted challah boards and T-shirts promoting the Jewish Community Center.

"We've had a lot of teen-agers come by," said Charles Stahler, 30, a social worker at the Jewish Vegetarians of North America booth.

"Mostly, they want to become vegetarians because of the killing of animals, and we talk to them so they don't feel so alone in their cause," he said.

"One of the major Jewish ethics is to feed the hungry and to be kind to animals," Stahler added.

"Did you know there were a lot of famous Jews who were vegetarians? People like Isaac Bashevis Singer. He said something like, 'I don't eat chicken for health reasons -- the health of the chicken.' "

The festival offered music by the Hebrew Academy Choir, a mime performance, an Israeli dance open to all, the chance to win two airline tickets to Israel, games and free blood-pressure checks.

The walkathon, the theme of which was the "Jerusalem Chai" -- the 18th anniversary of the reunification of the city of Jerusalem -- drew more than 2,000 participants.

They walked all or part of the route, which looped the Ellipse, from the Lincoln Memorial to the Capitol, and went past the Soviet Embassy.

The walkers included Lin Solomon, 44, and Bunny Chapman, 45. Together, they strolled along 16th Street NW at midday with their Boy Scout canteen, laughing and talking.

"We always come out for this," Chapman said. "It's just a wonderful day for getting together, in terms of Jewish community."

Yeva Feldblyum, who left her native Russia for a new life in the United States five years ago, sat under a striped tent and remembered her first sabbath service here.

"To see so many Jews in one place who felt free to be together -- it was exciting. I couldn't speak. I even couldn't breathe," she said.

The festival, she said, renews the spirit. "To tell you about our feelings here today," she said as her husband Izya nodded, "it's almost impossible to describe."