A few things to note:
-In SaveFileToolStripMenuItem_Click, you're referencing DialogResult. That's the dialog result of Form1, not of the open file dialog. Use "If SavLoadDialog.ShowDialog() = Windows.Forms.DialogResult.OK Then"
-Your images weren't uploaded to GitHub, so the solution can't find the images.
-Why not put those images in a separate folder for easier navigation?
-Don't be afraid to put different classes in different files, for easier management.
-Try moving the code in the If statement in SaveFileToolStripMenuItem_Click to a separate function that returns a List(Of G5_PC_PKM). And as codemonkey85 pointed out, it will be easier on you if you use a nested loop. Right now, if you need to change the procedure, you'll have to replace it in 24 or 25 different places. If that doesn't take away your sanity, nothing will!