I've seen where people have upgraded the storage chips on some Apple devices but never with an Android. I'm sure it is physically possible with the correct module and the skill to actually do it without ruining your motherboard. The biggest challenge I believe would be finding a memory chip that is not only the same physical size and pinout but also is compatable on the firmware side as well. You're better off rooting the tablet and learning some tips and tricks on optimizing your ram management.