Combine butter and minced garlic in a small saucepan.

Cook over medium heat until butter is melted, stirring occasionally.

Drizzle 2 tablespoons of the butter mixture over the salmon fillet.

Top the salmon with thinly sliced lemon.

Set aside the remaining butter mixture for basting.

Coat the grill rack with cooking spray.

Add soaked hickory chips to the grill according to the manufacturer's directions.

Place the salmon skin side down on the grill rack.

Grill, covered, over medium heat for 5 minutes.

Carefully spoon some of the reserved butter mixture over the salmon.

Cover and grill for 15-20 minutes longer, or until the fish flakes easily with a fork.

Baste occasionally with the remaining butter mixture.

While the salmon is grilling, combine mayonnaise, chopped sweet pickles, finely chopped onion, ground mustard, and Worcestershire sauce in a small bowl.

Mix well to combine the tartar sauce ingredients.

Serve the grilled hickory barbecued salmon with the prepared tartar sauce.