On the customer transaction list there is a column for memo, how can i write something in this column?

Welcome to the QuickBooks Community, fwgrafix. I will be happy to show you how to add a comment to the memo column for the Transaction List by Customer. Here's how:

1. Go to the Reports tab.
2. Use the search engine to locate the report.
3. Once the report loads, select the one you need to add the memo.
4. If you are using an Invoice or other forms, you can use the Message Statement area to add a note. 
5. If you are receiving payment, you can use the Memo area to add a comment.

Once you have done this and save the transaction, it will reflect this in the report, as seen below.

Please reach out to me if you need further assistance working with QuickBooks. I'm always here to help. I hope you have a lovely day. Take care.