Joy should greet the arrival in shops in the next few weeks of rTC "The Stories of Vladimir Nabokov," edited by Dmitri Nabokov (Knopf. 655 pages. $35). Edited by the great master's son, this will stand as the definitive collection of Nabokov's short fiction. Its 65 stories were written from the early 1920s through the 1950s. Of those, 13 have never appeared in book form before. To browse through them is to be transported to a heaven of grace and elegance of language and human insight, led by the hand by one of the richest and most morally provocative imaginations in the 20th century.