I have deleted an article in the first tab (Article identifier) and now it looks like all the data has ended up in the wrong place?

As a general rule, you should avoid deleting lines in the file. If you really need to remove an article from the file, you need to start emptying the information associated with that article in the criteria tab furthest to the right (Emissions and tests) and work your way to the left, to finally remove the article from the first criteria tab, Article identifier. Otherwise, all the information in all tabs will jump up a line and consequently be imported incorrectly into the system.