Maybe can help you!

    How To Hard Reset Your Samsung Galaxy Tab 2

    Switch Off Your Mobile Phone
    Take Out Your Sim card And Memory
    Press And Hold Both Volume Keys +Power Button
    When You Got Android Recovery Menu . Release  All Keys
    Scroll Selection To Factory reset /wipe data Using Volume Key
    Confirm Selection Using Power Key
    Then Select  Yes -- delete all user data And Confirm
     Wait Some Seconds. Then Select Reboot System Now Option And Confirm
    Now Your Phone Will Restarted. After Completing The Hard Reset Process
    Done ! Enjoy