I assume this is the HEOS speaker by Denon? If so, it should work with a variety of sources including music stored on the tablet not just Spotify Premium. The only issue is it looks like that tablet by default only has 8GB of storage so if you want to go this route you'll need to buy a micro SD card for the tablet, 32GB storage would be under a tenner although if you have a particularly large music collection or you'd like store videos on the tablet as well a 64GB card is only around £15.
John