The first wet coat of pigment stain fills all depressions in the wood within seconds. Letting the stain remain longer on the wood won't darken the wood more because the depressions are already filled. The same is true for the second coat. You are seeing the results of using a specific stain on a specific species of wood. If you plan on doing any future staining, go get the book "Understanding Wood Finishing" by Bob Flexner.
Maple is a pain. You might be able to darken without resanding if the stain you are using is a pigment based gel stain which penetrates very little with a coat of a darker oil stain such as Minwax or Watco which might penetrate some in addition to what is already in the wood. Experiment with what you have with Jacobean Minwax second coat or Dark Walnut Watco second coat. Experiment on bottom of table top or piece of scrap wood you acquire somehow. Keep in mind that if your table top is a veneer, you will in short order sand thru a layer. And heed the advice of everyone that if you are using a water based stain or finish, do not use steel wool!!
With a bit of experimentation, your finishing abilities will quickly improve and become more satisfying...if you are going to do much of this, buy the book. Luck, Kizmet