Yeah, so for example: "Do you fancy going for a walk", "Do you fancy getting a pizza" "Fancy that!" has a meaning akin to surprise, so for example: "Do you know Jenny was getting married next month?" "No, fancy that!"

It's an extremely rare phrase in America. 'Fancy meeting you here' is the only way we use it.

Do you fancy going for a walk? or We can go for a walk if you fancy it. They have just been walking for 5 hours. "Well, fancy that!"

¿Te apetece ir al cine? Do you fancy going to the cinema? Me apetece una taza de té. I fancy a cup of tea.

Do you fancy = would you like to/would you like a... Fancy that = expresses surprise, disbelief or shock and is used as an exclamation.