In this simple diagram of a drilling rig, #20 (in blue) is the rotary table. The kelly drive (#19) is inserted through the center of the rotary table and kelly bushings, and has free vertical (up & down) movement to allow downward force to be applied to the drill string, while the rotary table rotates it. (Note: Force is not actually applied from the top (as to push) but rather the weight is at the bottom of the drill string like a pendulum on a string.)
A rotary table is a mechanical device on a drilling rig that provides clockwise (as viewed from above) rotational force to the drill string to facilitate the process of drilling a borehole. Rotary speed is the number of times the rotary table makes one full revolution in one minute (rpm).
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