Save the position - it saves the position of cursor. Then you can jump to that position using Jump to the saved position menu item.
Links - here are names of local files from links in the current document - you can get them by Search > Scan for local links (I've described it previously). More of that, from this menu you can switch to yet opened (in TEA) document.
Go to recent tab - switch to the last accessed tab.
Focus the text/Focus the Famous text entry - useful, if you want to assign some hotkeys for switch between a text tab and the Famous text entry.
Go to the block start/end - really does it. For C-like languages or PHP. It moves the cursor to the current block's start or the end ({ and } characters). I think it is useful.
Open at cursor - if you have the link to a local file at your HTML-document, you can open it with this function. Just point to the filename in the text and use it (pressing F2 will be more quick). If you point to an image-file, it will be opened with built-in image viewer. You can also use an external viewer - setup it with Preferences > Commands. For example, it can be the command line display %s&. Also in that case you need turn on the option Preferences > Switches > Use external image viewer
If the file is not an image, Open at cursor open it in TEA as text file with a same encoding as of the current file's one. If the file is opened yet, it becomes the current one.
If you have a link to the local "a name=" - label, press F2 to jump to the place of a definition of that label.
Edit at cursor - the same thing as the previous one, but it calls for a file not the viewer, but the external editor. Go to Preferences > Commands and setup there the command line to run a such editor. Example of a command line: gimp %s&