First volume of Tennyson's letters reads like a Jane Austen novel; The Letters of Alfred Lord Tennyson. Volume I: 1821-1850, edited by Cecil Y. Lang and Edgar F. Shannon Jr. Cambridge, Mass.: Harvard University Press. 404 pp. $30.

This volume is the first in an edition of three, and it represents no mean literary feat. Lang and Shannon, professors of English at the University of Virginia, have organized this prodigious edition around those few extant bits and pieces penned by a poet ''who would as soon kill a pig as write a letter.'' In it, they have created a work as sparkling and witty as a Jane Austen novel. They observe the strict methodology required of a scholarly work, but vitality never succumbs to the abstruse, nor good humor to solemnity.

Volume I covers the poet's life from his youth in a country parsonage, where he was the fourth in a tribe of 12 children of a brilliant but violently embittered and alcoholic rector, to 1850, the year that saw publication of ''In Memoriam,'' as well as his marriage after a 14-year engagement, and his elevation to poet laureate.

As it turns out, Tennyson had an admitted distaste for the epistolary form. His letters routinely begin with the transparent excuses and apologies familiar to all delinquent correspondents - cries of postal inefficiency, accounts of immobilizing illnesses, untimely accidents, and letters gone astray. Many of the letters he did write were deliberately destroyed by his son and first biographer , Hallam. As a result, fewer than 250 letters (including fragments) written in his first 40 years, the period covered in this volume, have been located.

In a leap of scholarly originality and inspired editing, Lang and Shannon have assembled about these bare bones the flesh and blood of other letters - those of relations, friends, and business associates. The world around him teems with a Dickensian diversity, and it is rendered with the nice phrasings and attention to absurdities Jane Austen immortalized.

Consider this cast of characters, as presented in the book's Introduction, in a discussion of Hallam Tennyson's shortcomings as his father's biographer:

[He] kept back all information about his grandfather's drunkenness and violence, about his uncle Frederick's romantic involvements and Oedipal struggles, Charles's romantic escapade with the governess and, more serious, his twice-conquered opium addiction (and his wife's long decade of nervous collapse) , Arthur's alcoholism, Edward's insanity and long half-century of confinement, Septimus's indolence and morbidity, Mary's broken engagement . . . he was discreet to the verge of otherworldliness about his great-uncle Charles Tennyson D'Eyncourt, who in his manorial pretensions and dynastic ambitions became the laughing-stock of mid-Lincolnshire. Tennyson himself was frequently unkempt, dirty, gruff, boorish . . . and nearly always hypochondriac. . . .m

This is the stuff of ''Masterpiece Theater'' presentations. My own favorite espisodes are those involving the social-climbing Tennyson D'Eyncourts - uncle, aunt, and cousins to Alfred and the other Somersby Tennysons. Here is cousin Edwin to his brother George:

My Father has received the King's licence for himself and issue to take the name and Arms of D'Eyncourt. . . . I am very glad we have changed our name, as it gives us good position. . . . Besides which it will keep us in a great measure clear of the Somersby family who really are quite hogs.m

Uncle Charles writes to advise George of the correct pronunciation of their new name: ''[It] is like Ei - not A or i not d'anecourt or exactly d'incourt but as nearly that -Ei- as it sounds in Eight. . . .''

This is merely one of the subplots in a volume that is a literary delight and a marvel of narrative complexity. Lang and Shannon manage to lend drollness even to their footnotes. Following an obligatory recital in a 17-line footnote of a particularly prodigiously connected correspondent, the editors continue, ''With the fraction of the population not related to him by blood or marriage, Stephen Spring Rice was equally at home. . . .''

Lang and Shannon have made a major contribution to Tennysonian and Victorian scholarship while simultaneously presenting general readers with a novel and exuberant portrait of Alfred Tennyson's life and times. I urge you to read it.