Open the record list, switch to the list view, tick the checkbox at the head of the column to select every record, then click the Action button and choose Export. In the Export Data dialog pick the format, CSV or XLS, and move the fields you want into the export column, expanding a field to reach its sub fields. Tick I want to update data (import-compatible export) to cut the field list down to fields that can be imported back. Save a field selection as a template to repeat the export on other models. Odoo says a large export can time out and to run it in smaller batches when it does.
What it holds
Customers, vendors, quotations, sales and purchase orders, invoices, products, stock moves, employees and accounting entries, one model per business object.
Find the size
The export dialog shows no storage figure and no record total. Read the count off the list view's own pager, which prints how many records the model holds, and quote the row count of each exported file.
What to enter on the form
Odoo in records, and the year your company started using it. Seller form