Preheat oven to 400°F. Using a two-inch round fluted cookie cutter, cut 2 circles from each bread slice (reserve leftover pieces for crumbs).
In a one-quart saucepan over low heat, melt margarine with thyme leaves. With pastry brush, coat bread circles with butter mixture and place on a small cookie sheet. Bake for 10 minutes or until golden brown.
Combine shrimp with remaining ingredients. Shape shrimp mixture into 20 balls.