If what you really mean is "open a file that's not part of an Eclipse project", the Open menu is pretty much it. You can drag from the Windows Explorer to Eclipse explorer views, but that actually copies the file. The standard Eclipse package expects that most of your work will be done inside Eclipse projects. There might be a general-purpose file explorer plugin available, however. Check the Eclipse plugin websites.
When it comes to destroying a civilization, gas chambers cannot hold a candle to echo chambers.