For about 1,500 or so guests, the 41st annual Radio and Television Correspondents Association dinner may well be remembered as its most merciful. It ended at 10 o'clock.

In a crowd whose tuxedos looked distinctly unrented, it was unlike the White House Correspondents Association dinner or the Gridiron, when one lingers over the food until what passes for late in Washington and listens to speeches often best savored with a good dose of wine.

This dinner at the Washington Hilton -- from ravioli soup to French vanilla bombe -- was wrapped up in a swift two hours.

"It's a carbon copy of the White House Correspondents dinner, except that it's marvelously short," said Terrence Smith, newly converted to "CBS Morning News" from The New York Times.

"This is like television. It's a three-minute sound bite."

For some, however, it may not have been short enough. Entertainers Monteith and Rand, facing what has been described as one of the nation's toughest audiences, got tepid applause from John Riggins jokes and a routine about a D.C. taxi driver who spoke a variety of languages except English.

But the crowd roared when they depicted what appeared to be a standard scene in a dentist's office: a woman full of panic sits in what appears to be a dentist's chair, hyperventilates with the laughing gas and then finally appears composed and ready.

"Good morning, this is Phyllis George," the mock announcer intoned.

At Table 2, the "CBS Morning News" host reportedly smiled gamely, telling friends later that she was not offended.

Secretary of Health and Human Services Margaret Heckler also apparently weathered a skit on her marital problems.

Off base and sometimes off color, the entertainment made a number of guests yearn for Mark Russell, a humorist who knows the limits of Washington humor.

"There was no patter. There were no real jokes, no Mark Russell," complained ABC White House correspondent Sam Donaldson. "This dinner could just as easily have been held in Omaha."

Said Sen. Alan Simpson (R-Wyo.): "It was nice to be at the head table and not have to give a speech. This is a tough audience, deluxe."

Still some of the traditions for these events were maintained. In the hospitality suites, journalists cornered sources they have been trying for weeks to get on the phone.

Others continued the week's business. Rep. Les Aspin (D-Wis.), the House Armed Services Committee chairman who helped navigate the MX missile win for Reagan, greeted national security adviser Robert McFarlane with, "How are you, tiger?"

Former Democratic National Committee chairman Charles Manatt helped maneuver Republican National Committee chairman Frank Fahrenkopf over to meet Rep. Mickey Leland (D-Tex.), an ardent spokesman for liberal causes. Fahrenkopf feigned surprise when Leland acknowledged that he had no plans to go Republican.

Added Manatt, "Business looks easy to me compared to what the Democrats have to do to get back in shape."

For stargazers, accustomed to the traditional Washington competition for most powerful or famous guest at these dinners, the easy winner this year was NBC. The network not only garnered McFarlane, but "NBC Nightly News" host Tom Brokaw brought Chrysler chairman Lee Iacocca, the subject of a Time magazine cover story this week.

Cabinet members at the head table included Treasury Secretary James Baker, John Block of Agriculture and William Bennett of Education.

President Reagan did not come this year, leading some wags to suggest that he favors election years for such events.

But others, like Gary Schuster of CBS News, offered the explanation that he prefers more traditional events like the Gridiron to the radio and television dinner, which has been held for only 41 years.

"He likes to go to the stuff that's older than he is," said Schuster, smiling.