Tap the menu icon.

Tap Gallery.

Go to the required folder.
Tap and hold the required file.

Tap the share icon.

Tap Bluetooth.

If Bluetooth is turned off:
Tap OK to turn on Bluetooth.

Your tablet now searches for devices and after a moment, a list of Bluetooth devices within range is displayed.
Tap the required Bluetooth device.
The file is sent.

Tap the home icon to return to the home screen.