By default, the Stock item form for a selected stock item, will display the Ledger, Document groups, Image, Multi Groups and Backorders tabs below the Stock information section.  

stock-use-tabs-default-setting

To change the interface of the Stock item form:

1.On the Setup ribbon, select Stock information.

2.On the Default tab; in the "Documents setup" section of the "Stock information" screen; deselect (remove the tick) in the "Use tabs in stock" field.

stock-use-tabs-option-stock-information

3.Click on the OK button. The Stock item form for a selected Stock item will change as follows: 

stock-use-tabs-option-not-selected-form

You may need to reopen the Set of Books; or go to the Tools → Close active forms menu (Setup ribbon), to close the Stock items before the changes will take effect.