The ornamental design for a boxshapeddisposalbin for a tabletop, as shown and described.
FIG. 1 is a perspective view of the box shaped disposal bin for a tabletop of the instant invention;
FIG. 2 is a top view thereof;
FIG. 3 is a bottom view thereof;
FIG. 4 is a right side view thereof; and,
FIG. 5 is a left side view thereof.
The portions of the figures illustrated in broken lines illustrate portions of the box shaped disposal bin for a tabletop which form no part of the claimed subject matter.