You cannot monitor audio via the tablet. You have to find a way to connect back to the headphone jack on the CQ. How you do that could be any number of ways:
1) A long cable
2) A Bluetooth transmitter (i.e. Twelve South AirFly or similar) plugged into the headphone jack and connected to bluetooth earbuds
3) An In Ear Monitor Transmitter/Receiver system such as the Senheiser IEM G4, Shure PSM series, Phenyx Pro Stereo IEM
Personally, I use an inexpensive stereo IEM system (Phenyx Pro 900 MHz). With this, I can plug any headphones I want into the receiver pack. A Shure or Senheiser system would no doubt be better but what I have is fine for occasional PFL/Listen needs.
What works for you may be different depending on your setup and budget.