What is the standard value for uploading each product/service name?

This is how the import works with the same product and service name, jennyhan.

When importing Products & Services into QuickBooks Online, the original price stays and is combined with the new additions. You'll want to select Overwrite all values to merge any imported Product or Service with the same name as an existing one. Please follow these steps:

1. Click the Gear icon, then select Import Data.
2. Select Products and Services.
3. On the Import products and services page, select Browse.
4. Find and select your Excel file. Click Open, then Next.
5. Map your information. Your Field represents the headers on your spreadsheet. From each drop-down menu, select the one that matches a field in QuickBooks Online.
6. Click Next.
7. Select Overwrite all values for each product or service with the same name. Make sure everything looks correct because this can't be undone.
8. Click Import.

Also, you can only import 1,000 rows at a time, If your list is longer than that, split it up into multiple smaller files. 

For future reference, you can use reports to get the status of your inventory. Use Reports To See Your Sales and Inventory Status.

If you need further questions, let me know so I can help you.

Thank you for your help!!

Can we also update each category name of many Service lists at once?

When importing Product or Service, there's no category column.

Is there any other way to do?

Thanks for getting back to us, jennyhan. Yes, you can update the service lists category name! 

Let me share a few details on how to update the category of all your imported service lists at once in QuickBooks Online.

Since we're unable to import the category column, we can manually create it within QuickBooks. Afterward, we can assign multiple service lists to that category name. To guide you further, please follow the steps below:

Create category:

1. Go to Sales on the left panel.
2. Within the Product and Services tab, click More drop-down arrow.
3. Select Manage categories. Then, click New Category at the upper-right corner.
4. Enter the name of the category. Then, hit Save.

Here's the sample screenshot for additional reference:

Once done, put a check-mark to all service lists you'll want to categorize. Then, click the Assign category drop-down arrow and choose the category you've created for them. That will do.
 

For additional details about managing items and services in QBO, you can visit this article in your free time. Also, we can run the Sales by Product/Service Detail report to view activities that we've done to the service lists. To customize this report, you can check this article and learn more on how to include necessary and exclude some details if you want.

Let me know if you have more questions. I'm always free to guide and help you out. Take care and have a good one!