This panel displays all of the blocks included on the selected route. As well as the blocks in the header and footer of the interface. Blocks can be re-ordered and nested inside blocks that allow it, by dragging and dropping the blocks within the tree. You can edit, duplicate and delete blocks by clicking the ellipsis on the right of each block item.
To select a block to edit it's configuration, either click the block within the preview window or click the block in the tree. This will present you with the options for the block and allow you to customise it's content and behaviour.