Need an super portable keyboard

On breaks at work I like to play Beat X on my tablet which is the pc equivalent to Stepmania.

Im currently using a Perixx 805L keyboard which works ok, but I know its causing me to suck at the game. Its flat design hurts my hands and I cant hit keys as fast as id like.

It doesnt have to be foldable, but what are some super small keyboards that would work for being portable? It can be wired, in fact id prefer that over blutooth.

The tablet (Nvidia Shield) is 8" and I would really like a keyboard thats about the same size as the tablet if possible.

It doesnt have to be mechanical but it has to be better than scissor switches.

I have one of these. It has black mx switches and it stores the macros in the keyboard so you don't have to worry about compatibility when you plug it in to different OS's or hardware. They also make a 24 key version. The connection is a long Ethernet to USB cable so you would need to get a shorter one if that is an issue.

You could also try a rig closer to this

Or just a regular numpad keyboard.

http://www.amazon.com/gp/aw/d/B002XNJGRA/ref=mp_s_a_1_1?qid=1456385037&sr=8-1&pi=SY200_QL40&keywords=numpad+keyboard&dpPl=1&dpID=4153YpHVyYL&ref=plSrch

And one of these if you don't have a full sized usb port.

http://www.amazon.com/gp/aw/d/B00OZDUTMM/ref=mp_s_a_1_7?qid=1456385400&sr=8-7&pi=AC_SX236_SY340_FMwebp_QL65&keywords=usb+to+micro+usb+hub&dpPl=1&dpID=31B0uJQqXpL&ref=plSrch