They are indeed splendid, the lives led by the larger-than-life people in this new collection of short stories by Penelope Gilliatt, the British novelist and film critic for the New Yorker. In the title story, a 92-year-old English bishop is depressed because his Derby-winning horse will not eat since the pigeon who used to sit on his back during meals has died, but he is cheered by the presence of a "pretty . . . revolutionary girl" whom he had met "in Trafalgar Square in a demonstration about Rhodesia" and whom he carries over a puddle so she won't spoil her "frock."

That is just the beginning. There is also a young boy abandoned by his jetset parents and living with his tutor on a Caribbean island; he conducts a public burning of a large sum of his father's money in order to get his attention. In another story, a gradnmother, in an effort to keep her young grandson, withdraws her life savings and shuttles the boy back and forth off daily flights between New York and Rome. Then there is Mr. Rossiter, age 82, his wife "Mr. Big Director," and the strange group of elderly folk who call him on his phone-in radio show.

They are all, in their own ways, splendidly improbable lives, and the stories about them are amusing, even at times hilarious, in a quiet, British sort of way. Still, one doesn't quite know what to make of them beyond that; the stories seem to end at an arbitrary point, leaving one wondering what the point in fact was. I suspect that Gilliatt doesn't intend to make one, and that has its own virtues, though one wishes that behind the charming surface the characters had more dimension, more resonance.

The way to read Splendid Lives is one story at a time, delighting in its ingeniousness, expecting nothing more. (Coward, McCann & Geoghegan, $7.95)