DEAR ABBY: After spending hours preparing a meal, is it appropriate for your guest to cover the food on their plate with salt and pepper without first tasting it? Beyond being inappropriate, isn’t it just plain rude? Should I say something? Never invite them for a meal again? Or just let it go? — IN A STATE IN THE GARDEN STATE DEAR IN A STATE: The next time a guest reflexively gestures toward the saltshaker without having taken a bite of your food, you would be within your rights to ask WHY. Perhaps your cooking tends toward the underspiced. If you are truly offended by this, no rule of etiqu…