The ornamental design for a protectivecase for tabletcomputer, as shown and described.
FIG. 1 is a first perspective view of a protective case for tablet computer 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;
FIG. 8 is a bottom view thereof;
FIG. 9 is a perspective view of another state of the protective case for tablet computer thereof; and,
FIG. 10 is a perspective view of further another state of the protective case for tablet computer thereof.
The broken lines shown in the drawings depict portions of the protective case for tablet computer in which the design is embodied that form no part of the claimed design.