The kitchen utensils in the picture with the wooden painted handles - what are they for? cutting a wiggley edge on something - but what? It was whilst wondering this that I realised just how much of our food is created wiggley. Now some of it is obviously to create more crispy crust. I used a pastry cutter in the kitchen for the 1st time in my life recently!!! I made scones for a Devonshire cream teas. When I was growing up we just used a glass tumbler upside down; why have another object when an existing one can multi task?
Lots of pasta shapes are wiggley - I know this is designed to hold sauce, so the shapes hold more or less sauce in their ridges and folds, but then some of it must be purely decorative - like zig-zaggy edges on ravioli. I suppose ridges in brioches and cakes help you to cut even sized portions, is that why jelly bowls have ridges - for serving slices? If I was an academic I think I'd take on a PhD on this, what fun the research would be!