The ornamental design for a wall mounted crafter's desk, as shown and described.
FIG. 1 is a perspective view of a wall mountable desk showing my new design in an unfolded configuration with the work surface in an horizontal position and a support leg in an vertical state extended from the work surface;
FIG. 2 is a front view thereof;
FIG. 3 is a rear view thereof;
FIG. 4 is a right side view thereof;
FIG. 5 is a left side view thereof;
FIG. 6 is a top view thereof;
FIG. 7 is a bottom view thereof;
FIG. 8 is a perspective view thereof with the work surface and the support leg in a closed or folded state; and,