Bob is your uncle

...And Bob's your uncle is an expression of unknown origin, that means "and there it is" or "and there you have it." It is commonly used in https://en.wikipedia.org/wiki/United_Kingdom and https://en.wikipedia.org/wiki/Member_states_of_the_Commonwealth_of_Nations. Typically, someone says it to conclude a set of simple instructions or when a result is reached. The meaning is similar to that of the https://en.wikipedia.org/wiki/French_language expression "et voilà!"--- Wikipeda

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This is the explanation from Wikipeda, but I don't understand the usage of it, and the definition of it.

Q1. What does "there it is" mean? = Here you are?

Q2. If someone say something correct, can I say "Bob is your uncle"?

Q3. My friend Peter asks me to give him a cup of coffee, can I say "Bob is your uncle"?

Q4. Is it rude if a waiter says "Bob is your uncle" to a customer in a cafe or restaurant?

Q5. Do Americans understand this? Wikipedia says it is commonly used in the UK and commonwealth countries. The US is not a commonwealth country.

Thank you!