Sovrin does not batch transactions, rather individual transactions or perhaps batches of transactions are posted to the ledger as they are submitted. This is because there is a fundamental difference between it and Bitcoin / Ethereum. These ledgers are dependent on proof-of-work to control posting of transactions, while Sovrin is not. Instead, Sovrin is a permissioned ledger, which we believe is a much more efficient, as well as trustworthy mechanism for identity. The validator nodes on this ledger are maintained by vetted stewards, selected for stability, reputation, and diversity among other factors. Each steward is allowed a single validator node.
With this setup, there is no need for the overhead of forming blocks and doing proof-of-work computations to post them.
Regarding the ledger contents, there are in reality 3 ledgers, with a 4th possibly added in the future. All but one of these contain metadata, such as information on the nodes that form the pool. The main ledger contains the contents listed by @nhelmy.