I can't see the tam, so I don't know what shape it's in, but if it's pure wool, a good washing in cold water won't hurt it, as long as you don't dry it or something like that. Just put it in cold water, soak it good, and make sure it's wet. Rinse it really well in the water. Just let it air dry.

You might try a little Febreeze and give it a turn in the fresh air outside first if you're afraid to wash it. Nothing like fresh air to remove the smoke. (We do that with our sweaters if we go somewhere that allows smoking inside.)