While it may be true, as the authors imply in "Eye on Cavett," that Dick Cavett is among the most urbane and literate of television celebrities, the smug tone of this second, rambling volume of opinion and reminiscence hardly seems justified.

When he's not talking about his acquaintanceships with the show-biz likes of John Wayne, Bob Hope and Woody Allen, Cavett presumes to lecture on the decline of written and spoken English, a curious chapter from a book that required a cowriter to help pound it into publishable form--Christopher Porterfield of Time magazine.

Perhaps in his peregrinations for PBS, CBS and, of late, HBO, Cavett simply cannot find the time to write a book by himself . . . though one would hardly suspect so from the seemingly interminable accounts of his time-consuming hobnobbing with the great (Tennessee Williams, George S. Kaufman, Groucho Marx), the near great (Jean Stafford, Peter Ustinov) and the merely famous (Fred Silverman). He frequently adopts a long-suffering posture toward members of the latter persuasion, balancing an irritated air of superiority with the aw-shucks hero worship he reserves for the certifiably brilliant, those fortunate few whose names he cannot resist dropping at every conceivable opportunity.

That is not to say that Cavett has no business putting himself in such august company. Indeed, he has played television host to many of the people he gushes about. His association with them seems to be the raison d'e tre of this book, a work whose only discernible form consists of a beginning and ending set in Cavett's native Nebraska.

At the outset, we are treated to a surprisingly frank assessment of his desire for adulation at his 20th high school reunion in Lincoln; at the end, we go with him to scout locations for a TV special set in the Sands Hills. We are subjected here to pseudo-Annie Dillard ruminations on the wonders of Mother Nature, as compared to the horrors of a TV star's existence in the Big City.

Occasionally, he peers through the misty veil of time at friends and relatives from his Midwest boyhood. There is eccentric Uncle Paul, for one, who wasted his youth riding the rails. Cavett reveals that he often wishes he could have spent some time hopping freights himself. One can only wonder what on earth stopped him. This harmless romantic fantasy pales, however, in comparison to his account of a recent visit to a crippled schoolmate. The things he said to this man were bad enough, but the fact that he relates them is unforgivable.

Cavett is on safer ground in New Orleans, even if that venerable southern city is below sea level. His memory of Tennessee Williams is adoring and superficial, but unobjectionable on the whole. (We learn that Williams was a poor New Orleans tour guide and that he had a good sense of humor.)

But when Cavett relates the story of a gathering of transvestites in the French Quarter, he reveals a hopelessly self-satisfied, boorish attitude. He informs us that they were "funny, touching and a little sad." Gee, Dick, really? Perhaps this is news to the viewing audience at home, but readers tend to be aware of such risque' matters nowadays. That Dick Cavett clearly believes he is providing rare insight into the nature of the demimonde is perhaps as instructive of his middle-class world view as his tacit insistence that things were somehow vastly superior in the past.

He cites his tolerance as evidence of his sterling liberalism, and yet his descriptions read like something written 20 years ago. Furthermore, he quotes Dorothy Parker throughout, from time to time mentioning other members of the Algonquin Round Table, too. It takes no great stretch of the imagination to realize that Dick Cavett perceives himself as a noble heir to the Round Table tradition. He reminds us again and again of the sharpness of his wit, his cleverness with words, his grasp of the rhythms of language, and, of course, his disdain of those who fail to observe the niceties of formal English, and never mind those wild-eyed professors of linguistics who claim that the language is in a state of flux.

An example of Mr. Cavett's peerless prose, then, should serve as an example to us all. To wit: "One summer morning a few years ago, I awoke feeling as if I had been keelhauled through Death Valley beneath a square-wheeled dune buggy."

People who work on glass sound stages shouldn't throw brickbats.