Hi,
If you have the tablet configured with your google account, you should see an option to reset your password using your google account information. The method is described at the top of this website: http://visihow.com/How_to_unlock_Samsung_tab2_password_without_losing_data
If you do not have this option, you can do a factory reset on your tablet. However, be warned: this will erase all of the data on your tablet, so only use it as a last resort.
1. With the device off, press and hold Volume Up, Power and Home button.
2. Release the Power button when you see the Samsung logo, but continue to hold Volume Up until the recovery screen appears.
3. Use the Volume buttons to navigate the menu and select wipe data / factory reset. Press Power to choose the selection.
4. Press Volume Up continue.
(Information found [http://android.stackexchange.com/questions/78812/disable-the-screenlock-on-samsung-galaxy-tab-with-forgotten-password|here|new_window=true])
Good luck!