For loading the exact same data for reporting, you'll need to manually enter the data as a new form submission or use the API to programmatically import those records. You can also use Power BI or your downstream reporting tools to combine that CSV with the data that's coming from ODK.
For using the data that you want to use in a follow up (e.g., a previous list of households that you want to show in a dropdown list), you can attach that CSV as a form dataset. See https://docs.getodk.org/form-datasets for more.
We know bulk upload is something users want and we are currently laying the groundwork to make that possible in the future.