One gem to use to allow users to export table data, like reports, is FasterCSV. The only thing is that there isn’t a lot of documentation on it. Here is a great tutorial on it:
http://rubyglasses.blogspot.com/2009/07/csv-views-with-fastercsv-and-csvbuilder.html
The only minor issue I ran into was that I needed to add this line:
@output_encoding = ‘UTF-8’
under the format.csv part, like so:
format.csv do
@output_encoding = ‘UTF-8’
end