The ornamental design for a portable tamper, as shown and described.
FIG. 1 is a front perspective view of the portable tamper being shown attached to another portable tamper in a closed configuration.
FIG. 2 is a front view of the portable tamper, the portable tamper being shown in a flattened and in a closed configuration.
FIG. 3 is a back view thereof.
FIG. 4 is a side elevational view thereof.
FIG. 5 is a top view thereof.
FIG. 6 is bottom view thereof.
FIG. 7 is another front perspective view of the portable tamper being shown attached to another portable tamper in a partially-open, exploded configuration; and,
FIG. 8 is another side elevational view of a portion of the portable tamper in a partially-open configuration.