For multi column listBox use the list property in the UF initialize event.
Private Sub UserForm_Initialize()
ListBox1.List(0, 0) = "FirstRow, FirstCol"
ListBox1.List(0, 1) = "FirstRow, SecondCol"
ListBox1.List(0, 2) = "FirstRow, ThirdCol"
End Sub
Remember the row and column indexes are zero based. If you have a large
number of items to add, you might want to use list fill from a range.