I claim the ornamental design for a set of slabs, as shown and described.
FIG. 1 is a perspective view of a set of slabs;
FIG. 2 is a top view thereof;
FIG. 3 is a front view thereof;
FIG. 4 is a right side view thereof with the blocks placed side-by-side;
FIG. 5 is a rear view thereof;
FIG. 6 is a left side view thereof with the blocks placed side-by-side; and,
FIG. 7 is a top view thereof with its environment shown in broken lines.
The broken lines in all drawing views are included for the purpose of illustrating portions of the set of slabs that form no part of the claimed design.
The broken line showing of the like slabs in FIG. 7 view represents environmental subject matter. None of the broken lines form a part of the claimed design.