Happy New Year, vwfreek.
Something like this happened to my wife's device. It lagged, became unresponsive, began closing apps on its own, etc. I pressed the reset button and it became stuck in a bootloader loop. We took it back and exchanged it for another one that works great. It's a pretty decent device for the $.
The reason your device thinks it's a phone is that the android OS was designed primarily for mobile smartphones then later adapted for tablets. The developers haven't changed the code in the various versions to reflect which device it's on since v4.0.4 (for example) is found on both phones and tablets. This means they don't need two different versions of the same OS.