Document Library title
The document library block allows you to list all documents from a specific media library folder which you select using the Root Folder property.
Hide top-level folder will hide the folder title from the display. In this case "Documents". The block will display subfolders and you can click to list the contents.
Hide top-level files hides the files - not sure why you want to do that so maybe don't
Hide quick filter hides the filter you see below. This allows you to start typing to filter the list you see. Handy if you have a very large list of documents.
Settings Instruction
Hidden toggle: shows/hides block
Background colour: Adds a background colour to the whole block
Navigation title/Anchor: creates an anchor link that you can use to link to from a navigation object e.g. url#anchorlink
CSSClass: you'll not need to use this
Remove gap: Remove the top padding from the block so it sits tight to the preceding block.