Main Street Theater, located in the Galeria Shopping Mall, was formed in 1979 to bring a good standard of repertory theater to Westchester County. The season has opened with ''Kaufman at Large,'' a new one-man show by - and starring - John Lithgow. It re-creates a tumultuous day in the life of smash-hit comedy playwright and collaborator George S. Kaufman.
One-man shows are quite the rage today - the economics of theater being what they are, as well as the shortage of roles in relation to the fine actors available. A good deal of what Lithgow accomplishes as actor, playwright, and director in ''Kaufman at Large'' is commendable and entertaining.
Lithgow compresses into one day various summer events of 1936, when Kaufman was headlined because of Mary Astor's notorious diary, was worrying about his wife's and daughter's reactions to those headlines, worrying about his collaborations with Moss Hart (''You Can't Take It With You'') and Edna Ferber (''Stage Door''), and doing battle with a noisy substitute Hausfrau. The evening , culled from Kaufman's writings, is episodic, epigrammatic, touching, biting, witty.
It does not always hang together, and it teeters on sentimentality. Happily, Lithgow is a sensitive actor who keeps to the sober side of bathos. He seems nervous outside a role, however, so that his scene-setting before the opening is more hectoring than warmly confidential. It then takes too long for Kaufman to ''appear'' after Lithgow ''disappears.'' For this, a too-gentle edge for so uproarious, abrasive a man as Kaufman, and lapses in pacing, Lithgow is not the best man to direct himself in this venture.
Michael C. Smith designed the handsome set, Ann Roth the costumes, and Gregory C. MacPherson the evocative lighting. At its best, ''Kaufman at Large'' moves well, and keeps the audience engrossed. It is off the beaten track as an offering, but ''mainstream'' occupies the rest of the season, which will include Chekhov's ''Uncle Vanya'' (Jan. 27 - Feb. 21), Coward's ''Private Lives'' (March 17 - April 11), and Williams's ''The Glass Menagerie'' (May 5 - 30).