Hi Ronald.
A lot of people want to be able to store relational or hyarchical date in SharePoint, however as you have seen, SharePoint does not have a way to do this. SharePoint is built on a flat data structure to optimize it for browsing and navigation, and it works for light weight storage and simple lists. For more complex data structure and layouts it does not do so well. If you need more than that then the best option is to switch to a database server (SQL) since it is designed for such data. SQL has the perofrmance and structure to handle large volumes of forms 2K+, and relational data.
If you would like to see an example you can contact me directly.
Otherwise you are stuck building another list to show the repeating data but then there is not a relationship.