There is nothing special… you just install SambaPOS on them like they are another terminal. You install sambapos then point it to your SQL Server database. If you know how to setup multiple terminals then you can setup a tablet.
If you need help with setting up multiple terminals then first you need to install SQL Express 2016 and get SambaPOS to connect to it. Here are some tutorials for that. The first tutorial is for SQL Express 2014 but 2016 is latest version. You should get 2016 the install instructions are the same.