Can SQL Server Audit be used to track hostnames or IP adresses of the users performing DML on a table?
With SQLAudit you cannot track HostName or IP address.

However, there's an alternative method for auditing, based on streaming extended events. I blogged about it earlier this year. 

Basically, you treat locks acquired as indicators of the operations being performed on the tables (shared locks and schema stability locks for reads and exclusive locks for writes) and you capture these events with an extended events session. You will need to hook a script (or an executable) to that session using the streaming API and you can implement your own logic to filter, categorize and persist the events you're interested in.

Another possibility is capturing the "Audit Schema Object Access Event" events with a trace and streaming them to your own custom application. Here's a tutorial. In Extended Events the same event is not available, as it is reserved for the SQLAudit implementation.