"Well aren't you cute!" The woman replies to Odo then seems a bit shocked when the halfling excuses himself and moves on. "Halflings!" She says partly to herself, her voice one of confused wonder. No one really knows what a halfling is thinking... not even the halfling himself.
The most "gullible" looking man in the casino is a sleezy looking human dressed in all black, greezy black hair slicked back and hanging down past his shoulders. His face is covered in stubble and desperately in need of both a good shaving and a good scrubbing. Odo marks him as a man who seems to know a little about cards but not enough to actually be good... Humans seem to just have that smug look when they think they know what they are doing. As chance would have it, the same table the man is sitting at is the same table where Gemble is sitting. Or... perhaps it isn't chance at all.
"There be room, little fella." The dealer says politely, but his eyes belay his concern for having two halfers at the same table.
"Of course a pip of such a profoundly wonderful stature is welcome!" Gemble says. Halflings, unlike most everyone else, have a certain unity amoung themselves. As such, they have certain nods, winks, grins, and gestures that can be easily interpreted in most situations that a typical halfling might find themselves in... gambling is definately the most useful of those situations.
With his comment, Gemble grins and nods in such a way that Odo realizes the other halfling is asking him if he knows how to play cards... and by "play"... he probably means "cheat".