If you want to disable this feature, please refer to the following instructions:
Step 1: Access the editing interface in Word 2013. Click the FILE tab
Instructions for deleting the recently opened file list in Word 2013 Picture 2
Step 2: Click on Options option
Instructions for deleting the recently opened file list in Word 2013 Picture 3
Step 3: In the Word Options settings dialog , click on the Advanced option
Instructions for deleting the recently opened file list in Word 2013 Picture 4
Step 4: In the Advanced settings screen , pay attention to the Display setup group. At the Show this number of Recent Documents line , enter 0 to turn off the recently opened file list. Then click OK to save.
Instructions for deleting the recently opened file list in Word 2013 Picture 5
And this is the result
Instructions for deleting the recently opened file list in Word 2013 Picture 6
This trick can be applied similarly on Word 2010. Wish you success.