add validation list column and comments column to a power query exported table in excel.

I want to import data from SAP to Power query, and then extract that as a table to an excel sheet,

I want to also add a column that has a drop down validation list of items (usernames) for each record in the table, and another column where text comments can be added in the table for each record.

Can I add these two additional columns inside of power query as I construct the table?

The SAP data is just SQL structured data, several columns.