Mr. Sajak sits behind a desk as he chats with guests sitting on a long sofa to his right. Even the Sajak personality fits nicely into the Carson mold. His jokes can be pointed, but he conveys the impression that he doesn't take them or himself very seriously. Physically, Mr. Sajak is almost eerily ordinary. His haircut suggests Yale 1958. From certain angles, he resembles Frank Gorshin doing an impersonation of Dan Quayle. He is, in short, a very comfortable sort of fellow, holding in reserve the right to be terribly wicked.

His premiere show on Monday was a sometimes trying exercise in trying to provide a little something for everyone across these United States. Mr. Sajak opened with a neat joke. Looking at his watch, he announced that ''in less than one minute we will officially become CBS's longest-running show of the season.''

Chevy Chase undertook the arduous role of first guest, meaning he had to sit through the rest of the program. At one point, he raised his hand and asked, apparently seriously, if he could go to the bathroom. And in one of those surprising moments that pop up on talk shows, Mr. Chase revealed that, rather than serve in Vietnam, he wrested a 4-F classification from his draft board by falsely claiming, among other things, that he had homosexual tendencies. He allowed that he was ''not very proud of that.''

But before that uneasy confession had a chance to sink in, Mr. Sajak was interviewing Joan Van Ark (''Knot's Landing''), who described her role as a host of various parades and beauty pageants, often with Bob Barker. ''Tell him,'' said Mr. Sajak, ''that last batch of Grecian Formula is not working well.''

Then the Judds, the mother-and-daughter team who have a CBS prime-time special of their own, sang a song and chatted briefly, with the daughter looking more unhappy than ever as her mother plugged ahead cheerfully. Peter V. Ueberroth, the outgoing commissioner of baseball, allowed that he was in favor of continuing to sell beer at games and was basically against drug testing. It was at this point that Mr. Chase excused himself for a few minutes.