This allows you to add some additional restrictions on the server.  99% of the time , you will probably never use them and they should be left at their defaults.
The day of the week setting controls when the server allows connections.  You could for instance only allow connections on the weekend.  Download and Upload queueing is a feature that works with some FTP clients.  It prevents users from sitting on the server downloading thousands of files while other users can never get any bandwidth to download files themselves.  Caution though...some FTP clients think the server has dropped the connection if the user has been queued for too long.  As a result, it should be used only after testing to make sure it works properly with your FTP clients of choice.
Deny FXP allows you to prevent a user from using your server to transfer files to another FTP server instead of downloading the file directly.  Deny reserved ports keeps FTP clients from making your server potentially be used in a FTP attack.
Finally the filename filers allows you to control what files are allowed to be uploaded, downloaded or listed in directories.