When rotating the tablet the screen does not rotate.

Certain applications will only display in portrait or landscape mode regardless of the orientation of the tablet.   This is a limitation or a setting of the application.   To test for this return to the home screen and change the orientation tablet.  If the display rotates consult with the documentation of the application for orientation settings.

The tablet also has a hardware rotation lock and a software rotation lock setting.  The hardware lock is located on the right side of the device, beneath the Power and Volume buttons.  The device is unlocked when pushed up, towards the volume buttons.  The device is locked when the lock is pushed down and red is displayed.

To modify the software screen lock go to Settings.   Slide the Lock screen orientation to off if it is in the on position.  If the setting is grayed out the hardware switch may be engaged.  This setting also be checked by going into Settings and then Screen.  The Auto-rotate screen will be checked if it is enabled.  If it is grayed out the hardware switch may be engaged.