Abstract: This is a desk top tray set comprising trays and connector-spacer members for connecting the trays in vertically stacked relationship two or more tiers high. Each tray has a versatility that makes it universally applicable either for individual use or for positioning anywhere in the vertical stack. That is to say, a given tray, when equipped with removeable and replaceable plugs for the upwardly facing bayonet ports thereof, can be used individually or as the topmost tray in a vertical stack. When the bayonet plugs are removed, however the tray can be used in the interior or at the bottom of the stack. Moreover the plugs, once removed can again be replaced, and the tray thus restored to the top of the stack or to individual use. The tray is also designed to receive connector bayonets plugged in from above or below, so that each tray can be used at the top, in the middle, or at the bottom of the stack.