Does not look like Calibre Companion will do what I'm looking for either. Got a reply back from the program author . . .
Our app (CC for short) doesn't replicate all of Calibre's functionality.
It's meant for accessing Calibre's library, downloading its content and
then making it available on the the device running CC. CC doesn't allow
control of or interaction with other devices. The best you could do
would be to use CC to get the books onto your tablet, and then some
other file manager program to copy the books off your tablet and onto
whatever device is plugged in via USB
So, I'm still looking for an Android App for my tablet, that will allow me to manage books and transfer them to other devices.