The extensible table includes: a main surface (5) supported by a support base (3A, 3B; 3); a first auxiliary surface (19) and a second auxiliary surface (21), arranged underneath the main surface (5) when the table is retracted in a condition of minimum extension and coplanar and side by side to the main surface when the table is extended in the condition of maximum extension; a table extension mechanism. The extension mechanism includes two movable supports (15, 17) arranged side by side, each carrying a respective auxiliary surface (19, 21). The movable supports are supported and guided on the support base of the table for symmetrically and synchronously moving close and away the two auxiliary surfaces one with respect to the other during table extension and retraction movement. Each of the movable supports (15, 17) includes a lifting and lowering member (23A, 23B; 27A, 27B) of the respective auxiliary surface during the table extension and retraction movement.