To clarify, are you trying to Delete or Add transactions from the Banking tab in QuickBooks Online? If there's an item in For Review that you don't need to Add or Match, it can be removed with the following steps:
Exclude downloaded bank transactions
From QuickBooks Online, navigate to the Banking tab > For Review section.
Using the Filter (funnel icon), sort the list to only include the dates/transactions which you don't need.
Once you have the listed filtered, click the top-left box to select all transactions. On the Batch Actions menu, click Exclude Selected.
Using these steps, you can delete transactions from the Banking section that you already have in your register. Alternatively, QuickBooks Online allows you to Match items that are equal in date and amount, follow the link to learn more.
Please don't hesitate to let me know if there's anything else I can do to help you succeed. Thanks for coming to the Community, best wishes.