The ornamental design for a table lamp, as shown and described.
FIG. 1 is a perspective view of a table lamp;
FIG. 2 is a front elevational view thereof, a right side elevational view thereof being a mirror image of the front elevational view shown in FIG. 2;
FIG. 3 is a left side elevational view thereof, a back elevational view thereof being a mirror image of the left side elevational view shown in FIG. 3; and,
FIG. 4 is a top plan view thereof.
The appearance of the bottom forms no part of the claimed design.