Havent heard most of these phrases

Two groups have nonsense clues.
The phrase is IN the cards, not on the cards.
And what the H is a City or Maximum break??????

Bigz, 'on the cards' and 'in the cards' are idioms with the same meaning.

A 'maximum break' refers to the game of Snooker, and a 'city break' is a vacation or holiday spent in a city.

All information that a quick Google search turns up.

@bigz, City breaks are popular short holidays and to make a maximum break 147 [155] is a target in snooker.
On the cards is a common idiom for meaning something is likely to happen similar to in the cards. I hope this clarifies the issue?

Thank you WVPuzzler

I should say that it is a nice grid, I learned a couple of things from it. Than you, Buzzelli, for posting!