A detachable table device includes a foldable leg device detachably connected to a table top and operable to support the table top when in an extended state and to separate from the table top when in a folded state. A circumferential portion of the table top has an inner annular surface formed with a radially and outwardly extending annular engaging groove. The leg device includes a pivot unit for interconnecting at least three leg members such that the leg members are pivotable relative to the pivot unit to be angularly equidistant when the leg device is in the extended state, and to be moved toward each other when the leg device is in the folded state. Each leg member includes an engaging end portion disposed movably in and engaging releasably the engaging groove in the circumferential portion of the table top.