Yes. On an old-school carved top, it has it's greatest thickness in the area between the pickups, under the strings, and gets thinner out towards the edges of the body. Depending on how deeply carved the top is, the layer of maple may be no more than 1/2" thick at it's deepest point. There's very little mass to it, and its contribution to the tone of the instrument is negligible. On some guitars, the maple is actually a paper-thin layer of veneer.