A table with a central extension, includes a frame, two movable trays bearing on the frame and adapted to be brought close to one another to constitute a continuous surface on their own, or to be symmetrically brought away from each other, or independently of each other to enable the set-up of one or several so-called central extension(s) between the movable trays. The edges of the movable trays and of the extension(s) include at least one tab located on a first half of the edge and a groove located on a second half of the edge, the tab having a height increasing from its distal edge up to its central portion and decreasing from its central portion up to its proximal edge, and the depth of the groove being larger than the tab height, enabling an assembly by mortise-and-tenon joint even when the trays and/or the extension are deformed.