I think you can find that in big hardware stores like ACE, I believe it is called putty to fill in inperfections in the wood finish. I saw some for wood and for metal applications am not sure of the brand though.
For really small chips I tried some wood glue that is like putty but more malleable for my guitar and it hardens like a rock, really solid and up till now still good, you can even sandpaper it to smoothen the application. The consistency is like toothpaste. I let it cure for two days though to make sure it dried completely
Hope this helps! Cheers!