Read Bytes Non-Paging/sec are those bytes read by the Redirector in response to normal file requests by an application when ...

Read Bytes Non-Paging/sec are those bytes read by the Redirector in response to normal file requests by an application when they are redirected to come from another computer.  In addition to file requests, this counter includes other methods of reading across the network such as Named Pipes and Transactions.  This counter does not count network protocol information, just application data.