When u say multi master can i add an item in CA and it reflects back in VA region ?
Based on the demo lecture, once you enable Streams, you should be able to create a global table and replicate your DynamoDB originally created in the CA region. Then everything is replicated in the VA region.
Yes demo shows how you create a table in VA region, after enabling DynamoDB streams, items get replicated to CA region. If you then update table in CA region, items get replicated to VA region too, demonstrating Multi-Master capabilities.