We claim the ornamental design for a synthetic resin sheet, as shown and described.
FIG. 1 is a first image of a synthetic resin sheet showing our new design; and,
FIG. 2 shows the design of FIG. 1 in a position of use.
The broken lines represent environmental subject matter and portions of the synthetic sheet that form no part of the claim. The thickness of the synthetic resin sheet forms no part of the claim. The broken line showing of the bounds of the claimed design form no part thereof. The synthetic resin sheet does not include perforations.