Starting from version 3.1 , user can use inline edit feature for lists and related lists.

• Select (click at) list on the form builder (1) and check "Inline Edit" checkbox (2):

• Save the form. Form list is now editable.

On the form hover the mouse over the cell you need to edit and click (3), then type new value (4):

Click OK (5) or Cancel (6) button to save changes or to revert them back to initial values.