Mr. Weasley was looking around. He loved everything to do with Muggles. Harry could see him itching to go and examine the television and the video recorder.
"They run off eckeltricity, do they?" he said knowledgeably. "Ah yes, I can see the plugs. I collect plugs," he added to Uncle Vernon. "And batteries. Got a very large collection of batteries. My wife thinks I'm mad, but there you are."
Uncle Vernon clearly thought Mr. Weasley was mad too.
According to Collins dictionary, "there you are" can mean:
a. an expression used when handing a person something requested or desired
b. an exclamation of triumph
It seems to me that the second meaning (b. an exclamation of triumph) might fit for the context, but I'm not quite sure. How should we understand "there you are" in this context?