Hi Mistique
To me this is one of those things where it only affects you if you believe it will. It's like it is not true, unless you believe it, such is the power of thought! Like I believe that I read better at a table, with a yummy smelling candle burning, do I? In truth probably, actually really not! But I think I do.
I can't talk I am a reluctant smoker, I can't seem to pack up entirely, but I smoke outside and get very OCD about mints, washing hands and spraying perfume coz I can't stand the stale smell.
In purely pragmatic and physical terms, I guess it would effect your cards... ever cleaned windows and walls, heck even the glass on a mirror or tv screen. I have, (My ex smoked indoors) yellow grossness and yet I still smoke.
But I figure the cards might just get that really cool aged look before their time
I once a very long time ago picked a tarot reader at a fair coz his cards looked so well worn. lol
If it really bothers you, try to read in a smoke free environment and see if it makes a difference. But personally, I don't really think it matters. But I see that it is bothering you, because you call it an "unpleasant odour". I do think all our senses come into play in a reading, so maybe yours is your sense of smell, just a thought.