The <ReactDataGrid /> can show arowIndexColumn similar to the index column in Excel & Excel-like apps - this column can be used for resizing rows via d&d, but also for restoring the default row height, by double-clicking the resize indicator.

The column can be easily customized, as you can do with other special columns like checkboxColumn.

Additionally and most importantly, you can specify a custom render function for the row index, using rowIndexColumn.renderIndex(index) prop - see the demo below for an example.