I think* kippers are like smelts? Little fishes. I don't mind them, just not in the morning. The only part of a traditional Japanese breakfast I couldn't stomach is the piece of soy simmered mackeral. Ewww.

A salt cellar is just a tiny, like @ 2" wide, bowl to serve salt. They're also easy to come by at antique stores cheap. They can also be re-purposed as candle holders/ tea light holders, too. Not sure when "shakers" came into being, but I'd guess like a lot of things, it started with soldiers on the battlefield in WW1.