Perhaps not unique to Czechia, but unlike in the US we use the knife and the fork simultaneously. We don’t switch them, we just have the fork in the left hand and the knife in the right hand.
When you put the knife and the fork parallel on your plate, you signal to the waiter that you’re done with your meal, while leaving them crossed means that you intend to continue. So you can leave the toilet and if you have left your utensils crossed, your meal will still be there.
When there’s alcohol involved and people toast, everyone should clink the glass with everyone, while maintaining direct eye contact with the one you’re currently clinking. It’s considered rude if you don’t. Also never clink with other people over someone else’s arms.
Also not unique to Czechia, but unlike in the US, no one takes your card away when you pay, they just bring the terminal to you or ask you to come to the terminal with them. Someone taking your card out of your hand is kinda unimaginable.
Hegar