Lol, They are Victorian Fishing Line Winders. Their function (to my understanding) is to get the fishing line on your reel with just the right amount of tension and to keep your line straight while putting it on your reel.
They have modern day fishing line winders that perform the same function. I use an ink pen to hold the spool of fishing line to get it on my reel...lol
Here is a picture of a Vintage English Wooden Fishing Reel with brass:
I'm sure Bamber has more information on their function.
You've pretty much covered it, they were also used as line dryers. The top left one is a collapsible version for carrying with you on fishing trips.