So. Just how does a Jewish girl eat a banana?

Reporter Marlene Cimons knows the answer. But alas, it's wholly umprintable in a family newspaper, freedom of the press not yet reaching to dirty jokes told for $1 at a party honoring, oddly enough, freedom of the press.

The joke was being told last night at the "Buck-A-Yuk" booth, which was just down from former HEW secretary Joe Califano's "Joe's No-Smokehouse." In between was Sen. Robert Byrd (D-W. Va.), vigorously autographing his album "Mountain Fiddler" in the "Byrd on the Record Booth."

If this is beginning to sound like a carnival for adults, it was. More than 1,000 of them at $20 a head, swarming in the Pension building on G Street. Officially, it was the Washington Press Club's Counter-Olympics benefiting the Reporter's Committee for Freedom of the Press and at the same time, honoring the American Society of Newspaper Editors. There are about 700 of them in town for a serious conference, but they've sure been going out at night.

Unofficially, the carnival was a chance for the out-of-town editors to watch various Washington celebrities get hit with shaving cream, etc. in booths. There were also hot dogs, potato chips, free beer and T-shirts on sale that said "Reporters Do It on Deadline."

And now, some highlights from the booths:

Foreign Policy. Throwing a dime onto a map of the world and hitting Moscow got you a flight bag with an adjustable shoulder strap or a credit card holder "for collectors"; hitting the Philippines got you a special issue of Sports Illustrated; and hitting Alaska got you, for some reason, a datebook.

The logistics of this game were not entirely clear. State Department spokesman Hodding Carter, who was manning the booth and who has enough confusion with Moscow as it is, was not about to try to figure it out. "Don't ask me," he said, scooping a dime off the People's Republic of China. "I don't make the rules."

The Buck-A-Yuk. This was jokes for a buck, told by Art Buckwald. No press exceptions, either. "There is no such thing as a free interview," he said. "Give me a dollar."

The reporter dutifully did."Now," he said, "do you want the political joke or the dirty joke?" The reporter wanted the dirty joke, which was told by Buckwald's co-jokester Cimons, which was the unprintable one about the banana. So the reporter, pen in hand, asked for the political joke.

"I have a patient-doctor relationship with my clients," said Buckwald primly. "I can't reveal my joke to the press."

An anonymous source revealed later that the joke went like this: "You know why the Republicans won't nominate Gerald Ford? They're afraid his first act will be to pardon Jimmy Carter."

The Bingo Booth. This was beginning to look as scandalously boring as a real-live bingo game until ABC correspondent Sam Donaldson, who might be politely called the life of a party, took over. He grabbed a bull horn, rushed into the middle of the carnival crowd gathered and began an energetic bingo recruitment.

"Bingo!" he cried. "Bingo!" He spied an out-of-town female. "Bingo!" he called. "Right here, my dear! Your honor will be intact." An out-of-town editor standing nearby looked at him in mild amazement.

Other booths included a "Whip Inflation Now" set-up manned by Labor Secretary Ray Marshall. This was not the most popular booth, maybe because throwing a beanbag at a cardboard house that presumably had a cardboard mortgage of 17 percent on it was not exactly exhilarating.

Clearly more exciting was the People magazine booth nearby. For a small fee, you could get yourself photographed on the cover as either Miss Piggy or Burt Reynolds. Robert White II, the editor and publisher of The Mexico (Mo.) Ledger, opted for Miss Piggy.

"Don't you think that's beautiful?" he asked, showing his face imposed on the body of the famous female porker. A few might have disagreed. Anyway, White had an "11" on his cheek, going Bo Derek one better. It was signed with "M" for Joan Mondale, who was tattooing cheeks and other parts of the anatomy at the crowded "Joan of Art" booth.

By 9:30 p.m., after about 3 1/2 people had danced on a big floor that was going to waste, things started winding down. Buckwald, in fact, relinquished his joke booth to Assistant Education Secretary Liz Carpenter. Believe it or not, she was actually telling jokes from a joke book in front of her.

It was suggested that maybe she was cheating some.

"Cheating?" she said. "Do I have a joke on cheating?" She flipped through the book, in vain.

"No jokes on cheating," she said. "They've all left town."