Apple's iTunes doesn't like Google's Android.
But there are ways to transfer your music.
The easiest way is with a data cable.
Plug your tablet into your PC. You might need to go into Android settings & enable MTP Mode to transfer files.
Open Windows Explorer & find the Music folder on your Android device.
Open another Windows Explorer window & find your iTunes library (probably Music/iTunes/iTunes Media/Music)
Put the 2 windows next to each other and just drag & drop.
There are other methods for transferring your music.
Good tutorial is right here