White socks with sandals
 

This probably sound like a stupid question but need to know. Do men wear white socks with sandals in Europe?

Men shouldn't wear socks with sandles no matter where they are. It looks ridiculous. The point of sandles is to go open toe which can't be done if you are wearing socks.

Only while being a patient at a hospital.

Er, no sorry. No socks - not cool - but sprinkle a little talc onto the base of the sandal for a little more comfort.

I don't recall too many men with sandals and white socks, but wearing socks with open-web shoes (not sandals per se but the ventilated slip-on jobs) is pretty common among older people in Eastern Europe. Distinctive, but not terribly attractive IMO.