Keep cold foods cold on the buffet table or at a picnic by nesting serving dishes of food in bowls of ice. Use small platters and replace them with fresh refrigerated platters of food often, rather than adding fresh food to a serving dish already on the table.
Refrigerate or freeze leftovers in shallow containers. Wrap or cover food. In refrigerated storage at 40 degrees F or below, cooked meat or poultry can be stored three to four days, pizza three to four days, and egg/tuna/macaroni salads for three to five days.