Is it Possible to Add "spacers" in Menu 2 (catagory) Menu Items?

I have a horizontal menu just below the header but I don't have enough menu items to stretch the whole width of the theme.

Is there a way to add spaces in menu items so that the menu will stretch the width of the theme?

I like using percentages for the menu items. Just divide 100 by the number of menu items to give you the percentage to start with. You may have to reduce it a bit until it works.