Combine first 8 ingredients in large bowl. Mix in shrimp.
Marinate at room temperature 1 hour or in the refrigerator 5 hours, stirring occasionally.
Prepare barbecue with medium hot coals. Thread shrimp on narrow skewers. Grill until just opaque, about 2 minutes per side, brushing with marinade.
Line platter with spinach. Arrange skewers on platter. Garnish with lemon and serve.
