Assuming you've got row data like this:
string[,] rowdata = new[,]
{
{"1", "Kim", "5"}, {"2", "Tom", "7"}
};
You can add new rows like this:
public void AddSteps(string[,] passRows, int processStepId)
{
for (int i = 0; i < passRows.GetLength(0); i++)
{
tableA.Rows.Add(passRows[i, 0], passRows[i, 1], passRows[i, 2]);
}
}