Please, please avoid small talk. Small talk involves topics related to:
They don't care about stuff they don't have control over. They care about stuff they can control, such as such as what charity or foundation they want to start or what they loved most about their most recent vacation. Ask them about their family. Ask they about their visions, dreams, and ambitions.
Ask "unfoldment" questions. An unfoldment question is one involving the word "most".
"What did you like most about your stay?"
You can also use a word that ends in "st".
"What was the best part about your trip to England?"
Wealthy people love answering these types of questions. Wealthy people don't care about traffic jams or thunderstorms on the other side of the country.
Also, keep your questions positive.