1) concentrating table
2) shaking table
a device consisting of a riffled deck, usually inclined in two directions to the horizontal to which a differential reciprocating motion in a substantially horizontal direction is imparted
GRM: n. (1,2)
Note: the material to be separated is fed in a stream of water; the heavy particles collect between the riffles and are there conveyed in the direction of the reciprocating motion, whereas the lighter particles are borne by the current of water over the riffles to be discharged laterally from the table

 ENERGY TERM COURTESY OF ENERGY.EU