Abstract: A convertible tray cabinet that can be used as a salesman's case having a base and a lid for carrying a nested stack of jewelry trays, and which cabinet can then be converted to a jewelry case with sliding trays therein by removing the lid, discarding the base, placing the lid on its side and sliding said trays into said lid on a plurality of spaced-apart ribs on the inside surfaces of opposed sidewalls of said lid. The ribs are vertical when the lid is used as a salesman's case and are horizontal when the lid is placed on its side and used as a jewelry case.