It's a featherboard. Used to keep work tight against a fence, usually with the table saw or router. To make one, use hardwood, cut in a rectangle shape about 4" x 10", cut one short end at an angle about 20 deg., cut "fingers" about every 5 mm. (1/4") by cutting from the angled end towards the other end about 8 cm (2.5 in.) or so long. (see Ed's photo) You could make a slot in it so that the featherboard could run in the table saw slot.
~Julie~
~Julie~