What does Thorin say to Bilbo, and what lesson lies in what he says?

If you're looking for a lesson, I guess we need to look at the following text;

"..... There is more of good in you than you know, child of the kindly West. Some courage and some wisdom, blended in measure. If more of us valued food and cheer and song above hoarded gold, it would be a merrier world."

The lesson would be to enjoy life rather than chase after what you can have. All you need is enough to be comfortable and live merrily.