non existent page on my site

I have noticed that in Google analytics a page which is /?kofe=24-opzioni keeps coming up as content found. It is not one of the pages on my website as each page has a title.

I have also noticed that there are several of these Pages on Webmaster tools. I am wondering when a client clicks on this page what they are seeing

Does anybody know the significance of this code or if it is a problem or not? Many thanks