If you refer to Microsoft Tag Service , it is for mobile devices that has camera and you could just scan and it will read Tag. If you refer to any other application you could try install it in Windows 8 and see if it works and if not , try run as compatibility
mode.
It also depends on hardware design too, Microsoft Tag is designed for mobile devices so that you could use handphone to read tags , as for tablet the hardware must have camera in back to be able to scan barcode easily . It could be feedback for future
but as for now, Tag reader is only for Mobile Phone since people would always carry their phone around but tablets are big and people might not have them all the times with them.