To easily increase/decrease the number of displays or personal computers mounted on each desk, and to easily change the layout of tables themselves.

A leg body 10 is formed as a frame body to be detachably connected to the back of a desk D. A cable tray 20 is detachably mounted on the upper part of the leg body 10 for storing wiring cables P, and a lid body 30 is attached to close an upper opening of the cable tray 20. The cable tray 20 has a number of heat radiation holes 21 for radiating heat generated from the wiring cables P stored in the cable tray 20. The device also has a wiring brush part 31 for leading the wiring cables P into the inside of the cable tray 20 along the edge of the lid body 30 on the longitudinal side adjacent to the desk D.