SPEAK, MEMORY by Vladimir Nabokov. 316 pages. Putnam. $6.75.
Ego dictates all autobiographies, the good and the bad; the truly modest man keeps silent, letting his life speak for itself. The literary world can be grateful that Novelist Vladimir Nabokov is not all that modest a man. He is, in fact, a compulsive autobiographer. For the past 30 years he has been disbursing fragments of this book to an international assortment of periodicals, obsessively revising, editing and amplifying. Now in its final polish, Speak, Memory deserves to stand as a rare and precious specimen...