There's a new trend among certain Washington ladies' circles to include men at luncheons, teas and brunches - men with position, power and a little free time.

But Vivian Dinitz, wife of the Israeli ambassador, believes more in tradition than trends. She invited 110 people to a luncheon yesterday at her home in honor of Mrs. Menahem Begin, and all were women. Just like the old days.

"I still believe in women's lib enough to think that women are interesting enough alone," she said. "All of these women are important and I would get in trouble if I excluded any of then for a few men."

Most guets were meeting the newIsraeli prime minister's wife for the first time; and after the string of luncheons, teas and parties recently, they are beginining to understand her.

She , too, believes in tradition.

"We are already liberated in Israel." Aliza Begin said. "Women have always played an important role. It is worse on us because we must send our sons and husbands out and wait."

Mrs. Begin has been exposed to more publicity in the past few days than she is used to. She seems overcome by the attention, the long receiving lines. She greets guests with a husky, Shalom, and shyly averts her eyes.

"I've always tried to keep to the Greta Garbo image," she laughed after the lunchoen. "One star in the of it.

"The plain housewife is the underdog here," she said. "What greater contribution can you make to society than a family?"

She laughed about her images as behind-the-scenehousewife. Mrs. Walter Mondale, who sat next to Mrs. Begin at lunch, said she told a story about the early days of war in Israel.

A reporter stopped what he though was a"typical housewife with a shopping bag" outside her what she though about the outcome of the war.

"Why do you think I went the beauty parlor?" Mrs. Begin answered. "We are going to win!"

Though some may characterize her as a women who spends nuch of her time watching her husband's health and making sure he eats enough, she denies this with laugh.

"Oh I have a hard enough time trying to keep up with him; even if I try to watch him, it too difficult. he does not listen . . .."

Mrs. Dinitz' luncheon was more related than previous ones in honor of Mrs. Begin. Some of the faces were finally familiar to her, and the conversation was light.

The luncheon was attended by a diverse group of political wives and local Jewish community leaders. Besides Mrs. Mondale, MrS. Dinitz hosted Mrs. Robert Dole, Mrs. Arthur Burns, Mrs. Thomas Eagleton, Mrs. Walter Washington, Mrs. Bert Lance, Mrs. Cyrus Vance, Mrs. Averell Harriman and Mrs. Arthur Schlesinger.

Despite her pre-luncheon jitters about rain water caught in the patio tent, Mrs. Dinitz seemed to enjoy the party too. "I thought we were going to have Noah's Ark here instead of a Bedoin tent," she laughed.

She and Mrs. Begin thanked the guests for coming as they were leaving. Mrs. Beginreached out to touch an old friend and said. "You can come to visit us now (in Israel). We're not in the underground anymore."