

Bear in mind that they already have your home address, as they sent the tablet to you, that address is geolocated, and anyone with a phobe passing near you will have enumerated any wifi networks and possibly bluetooth too and geolocated those.
They already know what devices are around you unless there’s not been a phone within range since you got them.
You were sent the tablet in order to be able to access the the app they provide. I strongly suspect that it is actually a loan, and they will want it back when you are finished with it. Given that, you shouldn’t even attempt to root it. Use it for what it is intended for, gain some benefit from that, hopefully get your massager, and return the tablet when you’re finished with it.
Unless you deliberately give them more information, there’s not much new they can gain about your environment from the tablet. What you do in the app is going to be much more valuable data to them as it’ll give them information about you and your health that they could not gain any other way.
The way he’s sitting reminds me of the “I don’t always … but when I do I …” meme.