A system includes trays of a plurality of different widths and an unloading system for unloading cartons from the trays. The trays (20; 20′; 20″) each comprise a base (22) and a pair of end walls (30) extending upward from the base. The unloading system (200; 200′) comprises a plurality of fingers (202A-202I). Each of the end walls comprise a plurality of vertical slots (40) open to an upper edge of the end wall. The fingers are positioned and dimensioned to pass through the slots of the trays as the trays are delivered by the tray delivery conveyor to lift contents of the trays. The fingers are positioned so that some fingers pass through the slots of each of the different widths, but others pass only through slots of wider said widths.