Here is a link to the underside of a genuine Knoll Saarinen table. I believe all genuine ones will have the Knoll signature on the base and a Knoll sticker on the underside of the marble. I know this image is for an outdoor version but the indoor ones are the same. It certainly looks as if the one you picture is a copy.
http://hivemodern.com/pages/product7267/eero-saarinen-outdoor-round-dini...
If you need any help, please contact us at – info@designaddict.com