The ornamental design for a leaf-shaped plate, as shown and described.
FIG. 1 is a perspective view of a leaf-shaped plate, showing my new design;
FIG. 2 is a front elevational view thereof;
FIG. 3 is a rear elevational view thereof;
FIG. 4 is a left side elevational view thereof
FIG. 5 is a right side elevational view thereof;
FIG. 6 is a top plan view thereof; and,
FIG. 7 is a bottom plan view thereof.
The broken lines represent portions of the structure that forms no part of the claim. The boundary lines represent the bounds of the claim and also form no part of the claim.