In Post Production EDLs are used to communicate the edit of a TV Show or a Film or indeed any sequence of shots in a text format allowing the receiver of the EDL to reconstruct the edit with the media at their end. They are simply text files, but have some strict formatting which makes them difficult to read and difficult to wrangle with excel for example.
XML files are also being used more and more in apple workflows, but with an Avid Media Composer workflow you are pretty reliant on an EDL workflow.
For instance, I communicate with digital labs on a daily basis using EDLs to request specific frames to be sent to whichever VFX vendor is on the show. It's the most efficient way to say I want this frame to this frame from this clip on this day. The lab is then able to read the EDL in and the media should link up without too much trouble.
You may be in a position where you have been sent an EDL and want to read it into an excel file so that each clip is on its own row. Your starting place is within excel itself, choose the option to read in a text file and choose spaces as your delimiter. The result might not be exactly what you want as it won't be a single row per edit but at least this gives you a place that you can easily delete unwanted rows.
I will soon be launching an app for Mac OSX which will be your friend if you ever find yourself wondering how to open that EDL that editorial sent you.