Issue adding items to tables, adding to "Extra items" instead

Getting this output in console - https://paste.ee/p/vb2w5

Was trying to add items to loottables as normal, but I had added an item to "extra items" earlier. After that anytime I try adding an item it will add it to "extra items" instead. I noticed that console output directly afterwards. I reloaded plugin and issue ceased. Thank you for your hard work, this plugin is amazing and so are you