How to Change the Block Title or Name

You can change or edit the name of each block anytime you wanted. 

Click the block you want to rename to expand the toolbar. Go to the settings tab and right under it is a box where it says Section Title. This is where you can enter the new name or title of the block.

The next screenshot shows the edited Title. The builder automatically saves the changes so no need to look for a save button.

Trust this helps.