TableRow class in Flutter doesn't has height attribute. But the height of the TableRow is the maximum of the intrinsic height of all its children's.
For example, you can has sizedBox classess for all TableCell classes inside the Table Row:
TableRow(
children: [
TableCell(
child: SizedBox(height: 5,),
),
TableCell(
child: SizedBox(height: 5,),
),
]),