Merging Queries to reduce rows

Hi All,

I am currently merging queries to reduce the number of rows I am loading into Power BI and I am wondering if it is the most efficient process or not. 

I currently have an incident table with nearly half a million rows from only a few months or so of data (system migration), long term we will be reporting on the last 18 months of data from this source, so I expect the number of rows to reach the millions.

As a result I'm trying to reduce this by merging queries with a contact table (same source), to only filter by certain contacts the incident has been assigned to, opened by, closed by etc. But at this point I'm now doing mutiple merges as these fields are all GUIDs that need to be merged with the contact table to retrieve names and other information that I can use to filter by. 

I know from a modelling perspective not to ultimately load these in as I have a few different contacts tables as dimension tables in my model. But given that mering queries is so taxing and I'm doing it multiple times now I wondered if there are any rules as to what best practice is in this scenario.

I have been advised by colleagues that SQL views would be the best way to do this, but unfortantely I or an available colleague do not have the skills for that.

Thanks