The ornamental design for a side table, as shown and described.
FIG. 1 is a perspective view of the side table showing my new design;
FIG. 2 is a right side elevational view thereof, the left side elevational view being a mirror image;
FIG. 3 a front elevational view thereof, the rear elevational view being a mirror image;
FIG. 4 is a top plan view thereof; and,
FIG. 5 is a bottom plan view thereof.
The side table is shown with a symbolic break in its legs, represented by jagged lines. The appearance of any portion of the article between the jagged lines forms no part of the claimed design. The broken line portion of the figure drawings is included to show portions of the article that form no part of the claimed design.