It could be that people just want to get to know you but find it difficult (if you don't talk/say much). People are interested in other people and if you like vinegar on your fries, that can wander into the conversation when co-workers are having lunch: "Well, Fleury29 likes vinegar with her fries, too, you aren't alone in that, SusieQ! I still prefer ketchup."

If you don't talk to many people, it is easy to imagine that only your stuff is known, not other people's. But we're part of each other's world and have nothing else to "navigate" by? It's like we're all blind so we have to think and talk about who likes what on their fries so we can think about it better, see more choices, and decide what we might like on ours.

I would decide to be flattered that people are interested in me and, like gma45 says, just make sure I paid attention to what I said/did around those who were not friends yet. But people have eyes and ears and nothing much else to think about besides what's going on around them? Many comments aren't positive or negative, they're just "Oh, by the way" sorts of thinking out loud, hoping there are others there and we're not alone.