To hold an over table at the board of a bed at the time of not using and to use the table by detaching from the board and arranging between the upper crosspieces of side fences at both side surfaces of the bed corresponding to an interval between these side fences.

In order to house-hold the over table 3 at the time of not using, a recess 5 is formed on the side facing a floor part 4 of the board 2 at the bed 1. The table 3 is provided with an almost square table part 8 and mounts engaging means 10 for respectively engaging with the upper crosspieces of the side fences in the state of being freely movable back and forth on the both end sides of the longitudinal direction of this part 8. These means 10 are provided with a pair of cylindrical pipes fitted in the state of being movable back and forth to the table 8 and engaging edges fixed to the tips of these cylindrical pipes. Receiving parts which can be engaged with the upper crosspieces of the side fences are formed on the rear surface sides of the engaging edges.