The WriteToServer and WriteToServerAsync have overloads that accept IDataReader (seen in the examples), DataTable, and DataRow arrays (DataRow[]) as the source of the data for the Bulk Copy.
The bulk copy program utility (bcp) bulk copies data between an instance of Microsoft SQL Server and a data file in a user-specified format. The bcp utility can be used to import large numbers of new rows into SQL Server tables or to export data out of tables into data files.