I think you are putting the security of your wallet in a high level of risks with that particular action. Because if I'm not mistaken, you cannot access your wallet without the keys, so might as well you will type in your private keys. I dont think of any better security than using your own device to access your wallet, not the other machines specially in a gambling area. Just my two cents.
Btw, the topic tackles more on gambling, how about moving these in gambling discussions. You might get a lot of answers to your inquiry, theres a lot of gamblers in that particular thread.
I couldn't see the situation being high risk other than someone stealing the device through a wrench attack but it won't happen to most people when casinos have good security. If casinos do use Bitcoins instead of fiat in the future they'll only need deposit addresses it's never a good idea to expose your private key on a casino if it was asked. OP's idea on putting in your wallet or bitcoin address on the machine is similar to having your own gambling account and send bitcoins to it.