Datatable.acceptchanges() commits data to the table
Here's the documentation:
When AcceptChanges is called, any DataRow object still in edit mode successfully ends its edits. The DataRowState also changes: all Added and Modified rows become Unchanged, and Deleted rows are removed.
The AcceptChanges method is generally called on a DataTable after you attempt to update the DataSet using the DbDataAdapter.Update method.
So your actual database is unaffected.