First, set AutoGenerateColumns to false. Bind your columns explicitely:
private void BindTableData() {
dgv.Columns(0).DataPropertyName = "table_id"
dgv.Columns(1).DataPropertyName = "table_data1"
DataTable you_table_source = GetYourComboData();
DataGridViewComboBoxColumn cb = TrYCast(dgv.Columns(your_index), DataGridViewComboBoxColumn)
cb.DataPropertyName = "your_datasource_column_name"
If (cb != null)
{
cb.DisplayMember = "your_display_column_name"
cb.ValueMember = "your_value_column_name"
cb.DataSource = your_table_source
}