A table elevating device includes: a table, formed with a bottom surface, a first side edge and a second side edge spaced away from the first side edge; a support mechanism, vertically disposed for supporting the table, and at least including an electric pushing rod used for driving the support mechanism to be elevated; a driver, served to drive the electric pushing rod to be operated via electric power; and a controller, including a case body having a first case part and a second case part and disposed on the bottom surface, and a control circuit unit electrically connected to the driver; wherein, the second case part is formed with an expansion hole oriented to face the second side edge along an extending direction defined from the interior towards the exterior.