#Need help with datapack structure
lapis ice
keen cobalt
Since this isn't a vanilla data pack file, we cannot say for sure. Whether this can be done and how varies between different json files, and depends on what the game is looking for from that file. Since this json file type is added by Forge or a Forge mod, only Forge or that Forge mod can tell you the proper syntax it expects, including how/whether to add multiple entries.
You are once again asking in the wrong place