It was suggested by a YouTuber who doe's Mcreator tutorials to make a request here for loot tables support.
Can you see if it is possible to add loot table support one day, what I was looking for is below, but I thought I would add it for some context for what I wanted.
Issue comments
Hey @Memesaus,
You can easily make them yourself using procedures:
Vanilla Chest Procedure:
Added loot tables list for overrides on our wiki: https://mcreator.net/wiki/minecraft-vanilla-loot-tables-list
Overriding of existing loot tables does not work properly yet and not sure if it will, but custom loot tables do work.
1.12.2 was marked as a legacy by Forge Developers and we adopted their schedule last month so we are marking 1.12.2 as legacy (means only critical fixes) too and working on 1.14.4 as the main version after we fix some issues it currently has.
We will try to backport them to 1.12.2 too where possible, this is not one of such cases, at least not with more effort than making sense.
There are already quite some features that are 1.14.4 exclusive due to 1.12.2 not even having mechanics for them. Update to 1.14.4 and you will be fine.
For custom loot tables in chests in structures, this page can be helpful: https://mcreator.net/forum/52371/structure-chests
You can assign these loot tables to any vanilla or modded block, chest, container block, entity, fishing loot, entity, you name it. Just use the proper namespace and registry name and it will override loot tables.
You can try it out by downloading the snapshot: https://mcreator.net/download/snapshots
You can manually define loot tables using json and place the json in the proper folder as you would do for normal mods. We will consider adding support for loot tables in MCreator in the future too.