PAT JASPER`S LATEST poetry collection, The Outlines of Our Warm Bodies (Goose Lane, 98 pages, $9.95 paper), is made up of the sort of material that used to be presented in the form of a familiar essay or epistolary diary: It was the summer my first boyfriend kissed me under the lilacs next to the locomotive at the train station under a billion stars and I wasn`t sure if I liked it or not. ("Summer Song`) The juncture of present and pastrecalled is jasper`s topic. Proust, whom she frequently quotes, is her mentor. It is never clear why she is presenting her material as "poetry" with line breaks that neither reflect natural pauses nor counter her prosaic rhythms. And, since her eye turns outward and toward society, the introverted form of the "lyric meditation" is inappropriate. Is it possible that jasper`s unwillingness to cast her material in the form of fiction is due to the fact that so much contemporary prose seems filled with poetic devices - symbol, dream, fantasy, word-play, and chanting -none of which much interest Jasper? Is she writing "poetry" merely because she hasn`t a plot? Her writing is intelligent, perceptive, realistic, and pretty good prose. Her gift for material detail as a reflection of character should make her, eventually, an excellent novelist. Consider, for example, the beginning of "The Day," on a funeral: It`s raining, of course, as we rummage through suitcases trying to find clean stockings, a half-slip the right length. The details take over Details are Jasper`s strength, not eloquence.