I'm a long CSVI member, but have never had such difficulties as now to create an import. I'm trying to find documentation or Q&A which answers my question, I'm sure there is though

What I want is to have 1 file to import containing:
sku
category name
image
thumb
manufacturer
stock
price incl. tax
tax
currency
If I create a template I need to choose a custom table from which the fields are proposed, but I need to have fields from different tables as written above.
Can you put me in the right direction?