There are 2 ways to export Safari Bookmarks plist file into HTML file, the first one is the geeky way and the other is using third party application. Let’s see how it can be done.
The Geeky Way
Open your Terminal and execute this command line, which will add Debug menu to Safari :
defaults write com.apple.Safari IncludeDebugMenu 1
After relaunching Safari, you now can choose File ▸ Export Bookmarks… And the rest of the steps should be obvious.
Safari Bookmarks Extractor
Go to Arcadia Design homepage and download Safari Bookmarks Extractor (144KB). After that, the application clearly explains how to export Safari bookmarks.