We have have a few operations available to us via the buttons in the upper-right corner of the board editor:
Export: Export your current board data to JSON file. You can then Import the saved board data from the Create Board window.
Duplicate: Make a copy of your current board and place it in the current board's folder. You'll have to provide a name for your duplicated board.
Delete: Delete the board you're currently editing. Be careful! This operation is not reversible.