Shorby counts all of the clicks on your links inside of a Smart Page, and full removal of one link will affect your statistics. Also, you may need a particular link but only several times. With the Hide option, you will not need to remove it and then add back as well as it will save the clicks.
To hide a button, just choose this option while editing a page!
You can hide as many buttons as you need per a Smart Page.
In case if you want to delete a block entirely, click on the trash can at the upper-left side of the Block Settings window.