I am interested in this too.
The hub does not send current back to the computer for security reasons; so if you plug a device that supply current to the hub; it won't get send to all the plugs.
The only current that is coming in is from the USB connector FROM the computer (500mA max). So you can't possibly recharge the tablet with a simple usb hub.
There is a trick that can be done; where you route the power on the cable that goes to the PC, which does not go trough the hub circuitry. This means that you need an external source of power, which will recharge the tablet directly, while the tablet will supply power to the hub and all the peripherals attached.
This is just theoretical...you are in fact using in a bi-directional way, something that was not supposed to be used...in general data goes back and forth; while power goes always from the computer OUT. The tablet/phone is made in a way that the charger is on the same data port, which is in the opposite direction than a USB hub , that expect power to come from that port, not to get sucked away (I bet that any hub has a diode that does not allow the current to go backward, or an IC).
Solution: can't charge and use it to power devices trough a hub. You can power at most one device, using a simple cable, that has power and USB IN, but a hub and power the device at the same time is a risk that I wouldn't take, honestly. In principle it is feasible, but are you going to risk your tabled to try?
If anyone was successful and can give more insight, I would love to hear about it.