"I'd probably be more comfortable serving the lunch," Ann Buchwald told the audience at The Washington Post Book and Author Luncheon yesterday.

Buchwald was one of three authors served up as the real dessert of this luncheon for 700 or so at the Sheraton Washington Hotel. She was introduced by Post executive editor Benjamin Bradlee as "my pal Ann Buchwald -- what's his name's wife."

And she put it straight about herself and her co-speakers, novelist E.L. Doctorow and political reporter and columnist David Broder: "The only thing the three of us have in common is that we want you to buy our books."

Buchwald's book, "Seems Like Yesterday," is a reminiscence of her years of courtship and then marriage to Art Buchwald when he was a reporter in Paris. "I've done two brave things in my life," said Buchwald. "One was to go to Paris without a job, and the second was to marry Art Buchwald."

Art Buchwald contributed to this book. "We had a raging fight one night from one end of the hallway to the other in our nightclothes, after I finished the first chapter," said Buchwald. "He was yelling, 'That's not the way it was,' and I said, 'You're going to ruin my book. I called the editor-in-chief at Putnam and said, 'I'm going to give you the money back.' She said, 'Tell you what -- you write the book and don't show it to Art. Then he'll write his part and you won't see it until it's in print.' That's the way we collaborated."

"Husband/collaborator" was not present yesterday -- "he's in Las Vegas giving a very professional speech."

Fiction writers are "born liars," said E.L. Doctorow, whose latest novel is called "Loon Lake." "But we are the only profession forced to admit it." i

Doctorow spoke about his high school journalism class -- for which he wrote a vivid account of Carl, the stage doorman and music aficionado who worked at Carnegie Hall. The journalism teacher wanted to publish it in the school paper, so she assigned a photographer, but Doctorow insisted Carol was too shy.

"'Well, didn't he talk to you?' she asked," the author told the audience. "'No, not exactly,' I said. 'There is no Carl the doorman.'"

Said Doctorow, "It seemed so much better to make up that stage doorman than to go through the tedious process of interviewing him . . . But at the time I didn't think of myself as a born fiction writer, I thought of myself as a student with a grade of F."

"Loon Lake," he said, was born from "driving through the Adirondacks and seeing the sign 'Loon Lake' and responding to nothing more than the sound of the words."

On the political side, David Broder said, "I can't tell you what a pleasure it is to be at something where the main speakers are Buchwald and Doctorow, not Carter and Reagan."

Broder said he came away from his research for "Changing of the Guard," a book about young up-and-coming politicians, "more hopeful about our political future than about the outcome of this political election."

He denied that the presidential campaign was obscene. "There has been redeeming social value in this election. Reagan has learned that China is not that tiny island off Asia. Jimmy Carter has learned, in the nick of time, that when he said, 'I owe special interest groups nothing,' that didn't include the Democratic Party."