I claim the ornamental design for a barbeque grill plate, as shown and described.
FIG. 1 is a perspective view of barbeque grill plate in accordance with the preferred embodiment of the present invention, showing my design;
FIG. 2 is a front view of the barbeque grill plate shown in FIG. 1;
FIG. 3 is a rear view of the barbeque grill plate shown in FIG. 1;
FIG. 4 is a left side view of the barbeque grill plate shown in FIG. 1,
FIG. 5 is a right side view of the barbeque grill plate shown in FIG. 1;
FIG. 6 is a top view of the barbeque grill plate shown in FIG. 1;
FIG. 7 is a bottom view of the barbeque grill plate shown in FIG. 1; and,
FIG. 8 is a perspective view of the barbeque grill plate, with broken lines showing a grid for a barbecue grill that is unclaimed in and forms no part of the claimed design.