miscellaneous
You'll need some other stuff as well:
Jumpers (aka "shunts"), switches, ethernet cable
You'll need an ethernet cable (if you're using the all-in-one board) to link your tablet to the board. Pretty much any will do, just make sure you don't buy one that's too short. Think about where you're going to place the board and the tablet.
While you're here, it's worth noting that some tablets aren't entirely smart enough to realise when there isn't a network switch in place (a switch is a box that you plug your computer, printer, router, AOG box etc all into, and they can all talk to each other). The switch handles the crossing of transmit/receive lines automatically. But when you wire direct (a single cable from tablet to AIO, no switch), what you really need is what's known as a crossover cable. If you are lucky, most modern network interfaces will detect the fact they need to crossover and handle it accordingly, so any cable will do. But if you're totally unable to get a connection going between your tablet and AIO, use a crossover cable instead.
If you need an ethernet connection to your implement controller, then you'll need to use a network switch - a direct connection of course will only work from one device to another. Look for one that's 12V so you don't need to mess about with inverters and such. Also, you want a "gigabit switch", not "10/100" and definitely not 10 !