When comparing two different reports, its important to make sure that you are comparing apples to apples. In other words, for the two reports that you are looking at, make sure that you are looking at the same segments, audience and that its a true comparison.
You said Page Reports. Are you just looking at the page report? Meaning, are you looking at all traffic to those pages? Or are you looking at a Target Activities report that would show the visitors in the test. My point is that if you are looking at a Pages Report, you could be looking at people who visited the page you aren't in the test. This would explain why its lower in Target.
I prefer to build out a view for my Target Test in Workspace. Something like this. A saved report like this saves time and is easy to reference. Plus you can look at a lot of different metrics.
