TRIM crusts from bread; discard or reserve for another use. Use rolling pin to flatten bread slices to 1/4-inch thickness; spread evenly with margarine. Top evenly with ham and Singles; roll up tightly.
CUT each roll-up crosswise into four pinwheels. Thread two pinwheels onto each of eight wooden skewers.
PLACE tomato, cut-side down, in center of serving plate. Insert skewers into side of tomato to resemble the spokes of a wheel.