Thanks Abhilash. The first post 'jigsaw' layout is more like what I am looking for. The "Format with Multiple Columns" does give me some possibilities to control detail columns flowing from left to right. However I can only have one detail group. For the case below, I don't think it is doable.
Report 1, 2, and 3 - each of them is taking half page width. Report 4 take the entire page width, then Report 5, 6, and 7 take half page width each.
Or the right, report 2 has more data rows than 1 and 3. Everything gets pushed down.
