A lively little comedy about life among the celebrities has taken up tenancy at the lovely little upstairs Lambs Theatre on West 44th Street. Although Lee Kalcheim's ''Breakfast with Les and Bess'' is set in 1961, it recalls those upbeat stage pieces of the 1940s or thereabouts which looked with sympathetic humor on some current but less than earthshaking dilemmas.
The dilemma facing Les and Bess Dischinger (Keith Charles and Holland Taylor) is the threat that their breakfast radio talk show may be canceled in deference to the prevailing popularity of rock-and-roll music. Since the Dischingers dish it out from their sunny Central Park South apartment (a luxurious pad designed by Dean Tschetter), Mr. Kalcheimer can handily confine his two-act plot to a one-set production.
While Les and Bess are awaiting the vital on-the-air transatlantic telephone call from Princess Grace in Monaco, a strange young man in boxer shorts appears from the living quarters unannounced and certainly unexpected. Everything is perfectly right and regular, however, since the young man is Ensign Roger Everson (Jeff McCracken), newly and secretly married to the Dischingers' daughter Shelby (Kelle Kipp).
If ''Breakfast with Les and Bess'' rises above the script's description of a current movie as ''funny and trivial,'' it is because of Mr. Kalcheim's concern for the career crisis faced by the celebrity couple. Bess wants to go on being ''the world's busiest woman.'' Les would settle for his old job as baseball sportscaster, with occasional work on a long unfinished book. The Dischingers do reach a compromise of sorts, but not until Mr. Kalcheim has put them through their comic paces and kept his audience pleasantly amused in the process.
Under Barnet Kellman's smart direction, ''Breakfast with Les and Bess'' is played with comic dash by an attractive cast that includes John Leonard as the Dischingers' son, with ambitions to be a dropout, and Daniel Ziskie, who doubles as a tipsy visitor and an offstage announcer. Ian Calderon lighted the production and Timothy Dunleavy designed the costumes.