What I think you are trying to do is very dubious and might not even be legal.
You want to load the result table or rather just the results from that url and display it in your own page? If the site doesn't provide a public API to share the results and only the results as json or xml then you really shouldn't use their data.
It looks like the table is loaded with some kind of ajax call and that is probably why it works in the iframe and not in curl.