Data Analyst create table privileges in production database

 I have a data analyst who is requesting create table privileges in a production data warehouse. I suggested an inline view in his query, but his response was "I have the need now to aggregate up some data and then do some updating of it, and doing it strictly inline does not allow me to save and review results step by step.  I only get the end result which makes it harder to test the quality and validity of the data along the way." He also states "The reason I consider this a "trivial request" is this ability is something