What if you have your data in CSV format and convert it to HTML for display on the web page? You may use the http://code.google.com/p/js-tables/ plugin. Check this example http://code.google.com/p/js-tables/wiki/Table As you are already using jQuery library I have assumed you are able to add other javascript toolkit libraries.
If the data is in CSV format, you should be able to use the generic 'application/octetstream' mime type. All the 3 mime types you have tried are dependent on the software installed on the clients computer.