The API access to schedule tables is still limited. But ViewSchedule.Export method is added in Revit 2013. It would be usual to know the method is available.
public void Export(
string folder,
string name,
ViewScheduleExportOptions options)
You can create ViewScheduleExportOptions object to specify how to export column headers, delimit fields such as Comma, or Tab (default) and qualify text fields.
And here is a link for the extensive discussion of this topic:
http://thebuildingcoder.typepad.com/blog/2012/05/the-schedule-api-and-access-to-schedule-data.html