Big is Beautiful, and Stella--all 5'8"" and 199 pounds--is out to promote that message, in print and across country as spokeswoman for Lane Bryant. Here she advises on everything from underwear (get rid of stuff resembling ""posto-perative bandages"") to hemlines and makeup, singling out particular brands and using history to prop up her argument (""the bigger you were, the harder they fell""). Other well-upholstered ladies will appreciate her disdain for spindleshafts and necrophiliacs although not all will value her endorsement of ""contrology' or rush to brush their pubic hair. But this Wagnerian-chested heroine, who looks like she could eat Twiggy for lunch, writes with such robust good humor that she can't be overlooked--either way--and those sympathetic (she claims to speak for 20 million) will chortle when, after the mayonnaise treatment for her hair--such a ""magnificent aroma""--she rushes out for a club sandwich. Fits size fourteen and up.