Purpose of hinges under table?

[Wayne and Carolyn Mathews]

I just discovered two of these hinges under my table. They were folded up, so I never hit them with my legs or noticed them when I was cleaning the table's pedestal. As far as I know, my table doesn't swivel; it does have the extension leaf which slides out, but I can't see that these hinges have anything to do with that extension. The holes in them don't match up with anything under the table. Can someone tell me what those hinges are for?

(Yes, I have now dusted under the table!)

Carolyn