Hello @singhe,
If I understand correctly, you’d like tables C, D, and E to exist as-is (they are reference/lookup tables) and you only really need to create synthetic data for tables A, B (and scale them up from the original training data). The recommended approach is to use the ReferenceTables constraint, marking tables C, D, and E as reference tables. Then these tables will always remain their original size (~8 rows each) while the other tables will scale up.
Note that the ReferenceTable constraint is available in the CAG bundle, which is an add-on to SDV Enterprise. If you’re interested in SDV Enterprise, you can Contact Us.
BTW the memory and performance is better (by orders of magnitude) with the HSASynthesizer. So if you upgrade to SDV Enterprise, you may actually be able to run on the entire dataset – no need to subsample from the larger tables during the training phase.