Tablet computer protective casing

FIG. 1 is a first perspective view of a tablet computer protective casing showing my design;

FIG. 2 is a second perspective view thereof;

FIG. 3 is a front view thereof;

FIG. 4 is a back view thereof;

FIG. 5 is a left side view thereof;

FIG. 6 is a right side view thereof;

FIG. 7 is a top view thereof; and,

FIG. 8 is a bottom view thereof.

The broken lines shown in the drawings depict portions of the tablet computer protective casing in which the design is embodied that form no part of the claimed design.