Yes, there's a way to remove these unmatched downloaded transactions.
You can delete those activities by going to the Transaction list. Then check the STATUS box to select multiple transaction. On the bottom, you can use the Batch Actions to Ignore the transactions. Ignoring it allows you to delete these transactions.
Let me show you how:
Go to the Banking menu.
Select Bank Feeds and then Bank Feeds Center.
Choose the Financial Institution.
Click Transaction List.
Check the boxes of each transaction or check the box beside the STATUS column to check multiple boxes.
Click Batch Actions and then choose to Ignore.
Choose Yes to delete the transactions.
Also, you can uncheck the box beside each event if you want to keep a specific transaction in your Transaction List. You can also change the date to show transactions in a specified period.