Hello, Cristina, welcome to the English Forums! I can't help you with "handbags", apart from the fact that most people at the buffet were carrying handbags, thus were women, but I don't know what it implies. As to the "blue rinse", well many elderly women have their hair dyed that colour (blueish white), so I guess it means the people at the buffet were not very young and belonged to the coquettish aging women!
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