Bric-a-brac is knickknacks: little objects without any purpose except decoration. Some people love to collect bric-a-brac.
Do you know anyone who collects little unicorn figurines or other small knickknacks? Then you know someone who likes bric-a-brac. Bric-a-brac consists of little odds and ends crafted by artists. This is a mass noun: it's plural without adding an s, standing for all sorts of tawdry trinkets. The nice thing about bric-a-brac is you always have room for more since they’re tiny. An arts and crafts festival is a great place to find all sorts of bric-a-brac.