This example illustrates how to copy active cell value alone when row selection in WPF DataGrid (SfDataGrid).
All the record contents will be copied to the clioboard by default when the SelectionUnit is set as Row in WPF DataGrid (SfDataGrid). You can copy the active cell value alone by using the SfDataGrid.GridCopyCellContent event. You can remove tab character from the copied data by overriding the CopyCell method in GridCutCopyPaste class.
KB article - How to copy active cell value alone when row selection in WPF DataGrid (SfDataGrid)?