I have an issue with the tablet internal space, the system data is taking 9.5GB, eating my internal memory (per file enclosed). Is there a way to clean it, so I can have some additional GB for user use.
check folder /data/logs. On my tablet there are a lot of crash-logs eating internal space. You can delete them with a file manager with root privileges.
You have to check periodically because Android is not stable on this device.