The ornamental design for a shelf for attachment to the underside of a tabletop, as shown and described.
FIG. 1 is a perspective view of a shelf for attachment to the underside of
a table top showing my new design from the front, top and left side;
FIG. 2 is a perspective view thereof from the rear, right side and bottom;
FIG. 3 is a front elevational view thereof, the rear being a mirror image
thereof; and,
FIG. 4 is a top plan view thereof.
The intermittent features seen on the D-shaped end pieces from above, are
perforations through the tray, and the transverse lines on the underside
indicate notches providing fold lines.