How would I categorize booth vendors in my store who pay me a monthly fee to rent booth space and 10% of their sales?

I appreciate you for joining the thread, @3146782.

You need to treat the booth vendors as your customers since their paying you for their rent expenses. Here's how you can add customers' names in QuickBooks Online (QBO).

1. Sign in to your QBO account.
2. Click on Sales at the left pane, then select Customers.
3. Tap New, then fill in the information.
4. Repeat the same steps for other booth vendors.

Once done, you're now ready to track the transactions you had with your booth vendors. For the payments, you can deposit the amount directly to an income account. 

1. Go to the +New icon, then click on Bank Deposit.
2. From the Add funds to this deposit section, select the income account used for tracking the rental income.
3. Add the amount, then fill in the rest of the details needed.
4. Save the transaction.

You can also learn more about deposits from this article: Record and make bank deposits in QuickBooks Online.

If you wish to review the entries recorded for your booth vendors, you can pull up the Transaction List by Customer report or any account listing report such as Transaction Detail by Account report.

I'm adding this link for more hints while managing your QuickBooks reports: Run reports in QuickBooks Online.

If you have any other follow-up questions while handling booth vendors or rental income in QBO, let me know by adding a comment below. I'll get back to you as soon as I can help you again. Have a good one!