You can use the “Upload data as CSV” workflow. Just keep in mind that the CSV file must have headers identical to the field names in Bubble. Also, Bubble won’t parse the data for you if necessary. This means the solution will only work if your fields are text or numbers (and I’m not entirely sure about numbers either). If you have fields that reference other tables, you’ll need to parse the data manually.
I recently helped another user parse CSV data using backend workflows. You can check it out in this topic: