please create new topics for your questions. To create a new topic just press “+New Topic” button in the upper right corner of the home page. Iterations is a big subject. Your question, while related to iterations, is not related to the subject of this topic which is consolidating sheets of a spreadsheet, not multiple csv files. I will answer it here, but next time please create a new topic, instead of posting into existing ones. This would also make it easier for other people to find relevant answers.
If you’re expecting to see only the last row in each file, then the iterated project should return only 1 last row for file, not entire file. For this, you can use the “Trim table” transformation to keep only 1 row at the bottom. If you have multiple tables in the iterated project, make sure that in the “Iterate” transformation you’re indicating the table with 1 last row as the returned result, not some other table.