Openables are a type of "loot crate" item, that load their loot tables from data tags within the mod
There are currently 8 types of openables
What that means, is that datapack or modpack makers can actually CHANGE the loot tables to add custom drops, such as for the "Passive Spawn Egg Openable", you can add other mods spawn eggs to this using a datapack
Simply right click the item in your hand, and it will consume the item but also give you something new!
