Stains are often applied to enhance the natural beauty of the wood. They're sometimes used to cover dull wood also. When used properly, stains are especially effective in creating the illusion of depth in a light colored quilted or flamed hardwood like Maple.
On a light colored flamed or quilted wood like Maple, it is useful to apply a coat of black stain on the lightly sanded top, and then after drying, sand it to remove the stain from raised or softer portions of the wood. This will leave a slight darkness around the edges of the quilt or flame, enhancing the illusion of depth. More stains may be applied, in differing color combinations. There tried and trusted methods that consistently work, but there really are no set-in-stone rules.