QuickBooks Online lets you upload bulk products and services from a CSV file format. However, this process doesn't include a Category column.
You need to categorize each item after the import process. I highly suggest using the sample Excel file to see how your data should look like. After that, you can upload your products using the steps outlined below:
Import your products and services
Go to Settings⚙, then select Import Data.
Choose Products and Services.
On the Import products and services page, click Browse to get the Excel file.
Map your information by clicking each drop-down menu, then click Next.
Select Overwrite all values for each product or service with the same name. Make sure everything looks correct because this can't be undone, then hit Import.