Slow loading report - Should I put more dependence on SQL Queries?

I thought there was only one table in the original post?

I am concerned about this statement "with a table visual that has 20 columns, each column is a DAX measure"  - they can't all be measures, can they?  Some fields must be from dimension tables.

How many Fact tables involved ?

How many rows in the Fact tables?

What about identifying which individual measures are slow by starting with a cut down version of the table and adding measures one-by-one?

How about posting a cut down sample file and I'll have a look?