The difference (B) between optimal working height (A) and the table surface height (C) is determined by the size of the objects being handled. Thus several values may result for B ,each dependent on the particular item being handled and the optimal work method. Distance B should be adjustable to the height that allows the hands to be at the levels recommended for A above, most of the time. Bench cutouts or elevations should be provided to accommodate particular instrument that would be awkward to operate if placed on the bench surface.