The present invention relates to containers and, more specifically, to trays that can be arranged at angles over the range from 0 to 180° so that, through this rotation, different height positions can be obtained; that include ergonomic handholds, which allow an operator to identify, by touch, the proper side for stacking or stowing or adding trays, as required; a dual guide on the base of the feet, to prevent the feet from separating when the trays are stowed; a dual track or groove along the sides, to allow so-called “shoe” or “skate” elements to slide and to prevent the trays from departing from their position; socket parts (male-female), to ensure that the upper trays do not become disengaged during sudden movements and to allow the trays to be stacked to different heights; and stops or protuberances in both the upper part and the lower part of the tray, to prevent the upper trays from sliding freely along the groove of the lower tray or along its side, depending on their position.