Welcome ssuescott, what is it you are trying to diagnose? There are plenty of threads in the Vizio Tablets section dealing with all sorts of VTab issues. You may want to read through there to see if a specific issue you are experiencing is already covered.
I will add a few that let you know what's going on under the hood.
CPU Spy
OS Monitor
System Tuner
Kii Discovery
Sandisk Memory (lets you space available on almost all your cloud storage)
I also agree with the previous post re: Disk Usage. It takes some time to dig but you get a ton of info about what is taking up space.