Set password to unlock screen on Samsung Galaxy Tab

If you want only authorized persons can use your tablet, then put him a password to unlock screen:

In the Home screen, press the "Menu> Settings> Location and Security> Define screen lock"

Select one of the options, for example PIN:

Enter a series of numbers and press "Continue"

Confirm PIN, then click "OK" and voila!

Do not forget to preserve the PIN in a safe place and that in the future to unlock the screen first have to enter PIN

Note: To receive calls you will not need to unlock the screen, but to perform them.