Much more fun to wield a play sword than a carved letter opener, and this would be a good one to hang from a nail on the wall then take down to put it into action now and then. I assume this was carved for a child in order to do exactly that--and its tip appears to have taken a stab or two. Quite a lovely object I think, all carved from one piece of wood, and beautiful wood at that.
18 1/4" long x 2 1/8" across at handle, 3/8" thick. One small chip on one side of the very tip, pretty minor and not really visible from the flip side, otherwise excellent condition, if not antique I would guess pretty close to it.