imagine moving all the data from your multiple datasets into one table

but adding a column with an enumerator with a value inserted to match each of your previous other datasets.

now imagine using a filter on each table inside a list region grouped on a common value among the datasets(like an entity id) and imagine setting the filter to the enumerated value that you set when populating the table with from multiple sources. Now imagine the time you save from not having to hit the database on every sub-report call and the fact the "subreport" aka filtered tables show up in excel.

Think common table/common id column/enumertated filter column/filtered table within a region grouped on the common id column.

Walla