I claim the ornamental design for an activity packing list tag, as shown and described.
FIG. 1 is a perspective view of an activity packing list tag, showing my new design;
FIG. 2 is a front elevational view thereof;
FIG. 3 is a rear elevational view thereof;
FIG. 4 is a left-side elevational view thereof, the right-side elevational view being a mirror image thereof; and,
FIG. 5 is a top plan view thereof, the bottom plan view being a mirror image thereof.
The broken lines showing a logo in FIGS. 1-3 and graphics and items associated with a particular sport in FIG. 3 depict environmental matter and form no part of the claimed design.