Okay, I thought as much. Unfortunately, this is an Excel file, so you cannot read it while it is hosted on Github. However, if you convert it to a csv file, then you will be able to do it.
In case you don't know how to convert an Excel file to a csv file, it is fairly easy. Open your Excel file, then go to "Save as" in the "File" menu, then save it as a csv (comma-separated value).