Although I have enough the available storage does not match it On a Samsung note 10.1 with 32G when I go to settings I can see 25GB available storage. Besides that, when I am trying to copy files from my ubuntu box to the tablet (connected through the USB) I am getting an insufficient storage message. Checking the properties of the mounted volume I only see 200MB free on it.

How can I fix it?
with 32 GB when I go to settings I can see 25 GB available storage


Though the device is declared to have 32GB, part of that is reserved for the firmware. The entire 32GB are partitioned:


/system for the device-firmware
/recovery for the recovery (see: recovery-mode)
/boot for the boot image
/cache for application cache
/data for apps and their data (see: internal-storage)


The 25 GB you see are those from the internal-storage aka /data.

This answer only covers the first part of your question. For the second part, we need some more details.