This is one of my favourite expressions. Bits and bobs (or bits and pieces) refers to small objects or items that have no big value. It is what we say in Spanish “tonterías o cachivaches”.
For example: – What did you find in the shop?
– Oh! Nothing interesting, only some bits and bobs.
I will never forget how I learnt that expression. I was lying on the beach in Hastings on a wonderful sunny day in August when I saw a small child who didn’t want his mother to remove his pants in front of all the people there and his mother said: “Come on! Nobody is interested in your bits and bobs!”