In the UK eggs are sold at room temperature but the packaging states "keep refrigerated after purchase". Similarly there are foods which, once opened should be refrigerated.
While cured hams will be cured at a higher temperature than fridge temperature, and, so are shelf stable per se, the lack of control the supplier has on the hams after they have left their supply chain may mean they label for refrigeration firstly to remove some variables and secondly to ensure it's refrigerated after opening when the hams could become contaminated e.g. with Listeria monocytogenes.
Same with hard cheese like cheddar if you think about it. You might mature the cheddar at 13oC but you wouldn't recommend retailers and individuals store it at that temperature.