A milling machine table device comprises a rigid longitudinal body having longitudinal surfaces parallel to each other along a length of the body configured to be attachable to a vise; and two rigid legs of equal length extending from the longitudinal body in a fixed position, each leg comprising a portion configured to engage a t-slot of the milling machine table there beneath. Also, a milling machine table device comprises two legs of equal length extending from the longitudinal body, each leg configured with a portion configured to engage a t-slot of the milling machine table and indicators disposed in one of the body and the two legs, the indicators comprising an adjustable probe configured to indicate an orthogonal distance from one of a vise jaw and an edge of a t-slot to an end of the probe. A method for calibrating and squaring the device is also included herein.