Is there any way to create something similar to a sub summary that is viewable in browse mode?

Subsummaries are viewable in Browse Mode when in Form View. For List View, you'll need calculations involving GetSummary( ) and a way to determine when the field should have data and when it should be empty, so that the result doesn't display on every record in the list.

So I understand the GetSummary function part but, how do I implement that into my layout?

Determine when you want the calculation to display and when you don't. Put that into a calculation of Case( criteriaWhenToShow; GetSummaryCalc ). The field won't slide up or anything, but at least it will be empty when you want it to be.

The only problem is that I want the summary to be above a group of records similar to how it is in preview mode. I suppose I could enlarge each record but then I can't view as many records on the screen at the same time and there will also be dead space in all the records except the first. Is this right or am I not understanding

This is correct. As I said, the fields won't slide in Browse Mode. Subsummary info is best presented in Preview Mode, as intended.