Hey Samaco  You can go through this solution 
https://community.fabric.microsoft.com/t5/Desktop/LuciaCache-What-is-this/m-p/407091#M186509

Hi,

Have a look here, should answer your question:

https://community.fabric.microsoft.com/t5/Desktop/What-is-the-LuciaIndex-Power-BI-AppData-Folder-taking-up-17-5-GB/m-p/616464

If I answered your question, please mark my post as solution, Appreciate your Kudos 👍