Folders:

• Open Terminal Here: opens the Terminal in that folder.
• Open as Root: opens current folder in thunar with root(admin) privileges.  
• Search: searches for files and folders in that folder.
• Create link: makes a link to a folder.

Files:

• MD5 checksum: shows a dialog of the md5sum of the file for a minute and 30 secs.
• Print file: opens the xfprint settings to send the print job to the printer.(needs a default printer installed)
• Mount/Unmount ISO: mounts ISO files to the /mnt directory
• Install .ttf Font: Installs .ttf Font for the user or system.
• Create link: makes a link to a file.