Do not doubt for a moment that should this charger to charge your GT3, I tried with other less powerful chargers and charging does not do ... downright worse, with a charger for smartphone (S3 not genuine), it worked a few minutes and it has literally exploded! I heard a loud "pop", the tablet produced the sound indicating the disconnection of the power cable; the transformer smelled burned and the upper part was dislocated ... I was lucky that the tablet had nothing!
This charger is the same one that came with the GT3 and works flawlessly thanks to its output current of 2 amps, which is required to recharge the GT3 safely. The cable also functions for data when connected to a PC.
I never try to recharge a tablet with anything other than his original charger ;-) (with the output amperage required at least ...)