The ornamental design for a table for foldingchair, as shown and described.
FIG. 1 is a top, front and left side perspective view of the table showing my new design;
FIG. 2 is a top plan view thereof;
FIG. 3 is a front elevational view thereof; and,
FIG. 4 is a left side elevational view thereof.
The chair and portions of the table supporting brackets are shown in broken lines for illustrative purposes only and form no part of the claimed design.