Should I confront her? I can't make the question long enough but possibly caught my girlfriend in a lie/cheating about another guy. Or it could be her expressing herself in a way she never thought would be seen. 

You don't need to "confront" her about this. You used her electronic device without her permission and found something. If you want to know what's going on with her and the other guy, you will need to confess what you did and what you found. And since she's your girlfriend, you ASK her about this guy. You don't accuse - you don't badger - you don't confront. You ASK. Have a conversation about this. In addition, you should apologize for snooping.

After you've had your conversation and you're still not satisfied with what she's told you, then you go from there. But there's no need to jump down her throat without knowing all the details.

Well you are going to have to tell her what you've found.  Do it with calmness and understanding or it will just end in a stand off.  She might just feel secure in him because he is a friend, however relationships are very different to friendships because you get to know one another intimately.  Many people have an idea about a friend which they think may have been their true love if only they'd noticed.  However, it is easy to romanticise things when they are not reality.  Also by the sound of things he doesn't feel the same way for her. She also has you on her mind, it's not as if you are absent and she is cheating on you. It sounds like these are all just absent minded writings, of dreams, and maybe feelings of insecurity or fear of the future. It's all very wishy washy. So don't go in there with two barrels firing, don't make her scared to talk to you.  Be gentle and listen to everything she has to say.  Take on board what she says then take some time to yourself to decide what to do next. 

So queue a Saturday after being out sick for an entire week. I still don t feel great and I m just sitting downstairs watching TV. My phone is about to die but I don t want to go upstairs and get the charger. Little later I was grabbing the remote and I find my girlfriends iPad, which is always around and has no security on it. Didn t think anything of it. I watch some youtube and decide I like this song and wanted to save it for later. Go to notes to make a note of it and I find something. A note she had written about another guy. Basically detailing some of their times together. He s her best, and only, friend in his grad school class and I never anything about it. I read it and she talks about how they made pancakes together last week and how she absent mindedly touched his back and then she almost kissed him. But she saw me in his face and had a panic attack. Goes on about how she had a dream that he mad a girl and had a kid with her and how she knows they could never be together. The end. I haven t told her about this yet and I m not sure I should. Help?

First, do you have anything to gain here by telling her unless you want to lose her for good which may be what you want.  I admire your wanting to be honest here  but since nothing really happened and all this is is words, giver her the benefit of the doubt here as you two are NOT married so you don't own her  and you don't say if you two are having relationship problems or not .  She may be setting you up here too by leaving her phone where you can easily get to it and with no security.  Something wrong here but you have the most to lose here so do what you think you must here as youll have to live with the consequences, but personally, Id just leave it alone and move on and see if it happens again.  Good luck