It is possible to drag and drop files directly onto your computer browser to add files to unrealBook. To do this you need to enable expert mode.
Go to Settings->Globals->Functions and turn on expert mode.
Then go to the action menu and choose Open Web Interface.
A small window will appear giving you an IP address to type into your web browser on your computer. The iPad and computer must be on the same WiFi network.
Your browser will show a window containing the unrealBook files. You can drag PDF and MP3 into it. It is a listing of the unrealBook Documents folder.