Why is my tablet randomly restarting?

I have had an RCA Voyager Pro for about a year, and haven't had many issues. Recently I have been running out of storage space, but I don't think that could cause this. Often, when I'm in the middle of something, it will go to the screen after the logo and reboot. It takes longer than if you reboot it normally, so it's super annoying. Any help is appreciated!

[emoji137]Does it do it frequently enough to be worth testing it in Safe Mode?
Also, does it do it with no SD in?
It may also be worth doing a Cache Partition wipe, and a general cache clear in Storage, Cached Data.