Who can see the changes I make to the quote/invoice table columns?

On both the Quotes and Invoices page, you can hide and show table columns by using the button shown below.
edit-table-button
You can do this temporarily by making the desired changes and then clicking Apply Changes. This will affect the view within your own profile only - not the entire team's.

edit-table-columns

If you would like to change the layout for your entire team, then you would click the Save Columns as Default button. We recommend checking with your account admin before making this change!