Big looks good when you’re Bill Gates eyeing his double-decker yacht sitting in the bay, but maybe not so much when you’re handed a blind-date dinner bill that could be confused for a phone number. Chevrolet’s time-honored Tahoe falls on both the good and the bad sides of bigness. On one hand, it’s a comfortably appointed people hauler that features a full array of safety tech and entertainment treats. On the other hand, it’s hobbled by its pickup-truck origins and is an expensive-to-buy, expensive-to-operate giant with a . . .