Let them copy and paste it into a textarea. You'll end up with tab delimited data.
1. Use CFSPREADSHEET. Allow users to upload an xls file which is then read by CFSPREADSHEET. The data from the resulting query object can then be inserted into your database.
2. Use your database's import tools, if any. If your database supports importing data from xls you could let your users upload an xls file. Then use the database's import features to import the data from the spreadsheet. What database are you using?
Either of the options above would use CFFILE to allow the user to upload files to the server.
Will look into...
I am using MS Access