Billable Time Tab: Can't select all colunmns?

Hello, I’m looking at the Billable time tab, which presents all entries in a table. When I click “Edit Columns” I feel all fields in each Billable Time entry should be available, but only a subset is available. For instance, I’d like a column that displays “Hourly Rate” but that isn’t a column that is available to select. Is there a solution? If not, may I request the addition?

Thank You.