Biographers may spend their day light hours writing about others, but they spend their after-dusk and cocktail hours talking about themselves. Or rather, talking about their next book.

That's what they did last night, anyway, at a reception celebrating the publication of seven essays by biographers about how and why they write. The collection is called "Telling Lives: The Biographer's Art."

Under oils of George and Martha Washington at the National Portrait Gallery, a few of these assorted biographers (and at least one autobiographer) assembled with about 100 others to nibble cheese, sip wine, speak of things literary and promote whatever might be in their type-writers at home.

A book about American writers from the Civil until the First World War is in Alfred Kazin's typewriter in South Bend, Ind. Yes, Kazin, author of both "New York Jew" and one of the seven "Telling Lives" essays, lives in South Bend.

"Well, it's not exactly the most thrilling place," admitted the former Manhattan Upper West Sider. "And if you don't play football . . . "

Kazin has been a visting professor for a year at Notre Dame and will return to New York's literary womb in September.

The only other contributor to "Telling Lives" who attended the party spent the early part of the evening as a wallflower. "I m hiding behind the cheese," said Theodore Rosengarten. "This is the first publishing party I've been to in four years."

Rosengarten insisted he wasn't shy, just unconnected in Washington social circles. He wrote "All God's Dangers: The Life of Nate Shaw" (which won a 1974 National Book Award), and lives in a small-town in South Carolina. He has a look of earnestness about him and later was spotted making several Washington social connections.

Everyone else at the party had written a book, was thinking about writing a book, or was making money off somebody who had written a book. Literary agenst and editors were in abundance, as were other "biographers" who weren't connected with the collection of essays.

For instance, Kandy Stroud, author of "How Jimmy Won," instead of covering presidential campaigns, these days she's haveing a baby. "It's the ultimate creative experience - right?" said Stroud, who estimates she's one week away from delivery. In the meantime she's working on a Cosmopolitan magazine article about Sen. Edward Kennedy (D-Mass.) that will not mention anything about his sex life.

As for sex - or lack of it - CBS News correspondent and author Marvin Kalb had plenty to say. "I'm going to have less sex in the second novel than I did in the first. I think sex is passe. By my third novel, I may eliminate sex entirely."

When asked about his reported consideration to run for the U.S. Senate from Maryland, Kalb behaved like the government types he has covered for years. He denied everything.

"I'm not running," he insisted. "I have no plans to run. Zilch. What other negative thing can I say?"

The party, given by Kramer Books, New Republic Books and the National Protrait Gallery (the gallery and New Republic are publishers of "Telling Lives"), also brought out Alan Weinstein, author of "purgery" as well as Dan Moldea, who wrote "The Hoffa Wars." Moldea revealed he is working on another book, but still offered a tidbit or two on what he thinks really happened to Teamsters leader Jimmy Hoffa.

"He was crushed and smelted in a junked car compacter in Dettroit," he said. CAPTION: Picture, Alfred Kazin, left, with Janet Salinger and Marvin Kalb, by Joe Heiberger