Every application developed with Dynamics Mobile SDK, has a data model, describe as a number of business objects. Every business object has properties (members). The application may write data locally in the defined business objects, which are stored locally but also sent to Dynamics Mobile Platform as a Synchronization Packet, which describe the changes. The generated Synchronization packet is stored and processed in Dynamics Mobile Platform and is available for fetching by external systems ( ERP) via ERP API
The actual tables/entities in the Synchronization packet depends on the actual data model defined in the application as well as from the actual content included in the packet ( e.g. one or more entities).
Every application has a specific data model and flow - e.g. sends different syncpackets in different cases. So, when external system ( ERP ) is about to be integrated with Dynamics Mobile it has to be integrated with specific application and flow.