Hi willie8, welcome to Android Forums.
A lot of device manuals recommend charging overnight for the first charge out of the box. The manual for the Galaxy Tab 2 doesn't specify so you can go with what works for you. The speed at which it charges will have more to do with the charger. The greater the amps, the faster the charge, however, charge too fast and you'll overheat the battery and possible cause damage (including the possibility of setting it on fire
The chargers that ship with these devices are usually balanced for the optimum power, so I'd probably stick with that for the first few charges. That will give you the best indication of how long it will take. FWIW it could be as little as an hour and as much as 8 hours from 10% to full. Keep in mind you never want a battery to go to 0% charge. It could ruin the battery.