The way I read OP, he wants to know if he can get a tablet and just get a sim card for BVI use to put in that tablet. The answer is basically yes, if you buy an "unlocked" tablet, but you need to be sure that it will work with the provider network (Digicel, Lime).

In all likelihood, you already have a wifi enabled device in your possession. Your best bet, in my opinion, is to pick up a Digicel or Lime "mifi" device when you arrive. That is if your charter company or villa rental doesn't already provide. I know TMM does, check with your host.
JD, feel free to PM me with specific questions if you like. We've found something that works for us, happy to help if I can by sharing our experience.