This year's riddle book from Sarnoff and Riffins fills the left hand pages with their usual frenetic pictures and barrage of one-liners. In contrast, the right sides are bare except for a small sand-colored box on each page--wherein one Mr. Bigperson projects his memories of the bygone days of giants. ("". . . Some giants messed up the weather. Some giants spoiled picnics. . . ."") The joke is that Bigperson, concluding with ""I never see any giants now,"" stands up to reveal that he is one--but the whole sequence is dwarfed by the facing commotion, and the two sides relate not at all.