Serving Trays
A tray (also treef) is a flat object on which several cups or glasses can be placed so that the host, hostess or waiter can move them over a short distance, usually from the kitchen to the dining or coffee table and back.
According to the etiquette one should always use a tray, even if it only serves one or two cups which one can easily carry in hand. This does not apply to plates. One carries the tray on the left hand, so one can put the vessels with the right hand on the table.