If you want fix the width of each column of text, then the following code can be used
Dim animals As String() = New String() {"Cat", "Dog", "Horse"}
Dim fruits As String() = New String() {"Apple", "Banana", "Grapes"}
Dim line As String
Dim sb As New StringBuilder()
Dim spaces As New String(" "C, 20)
Dim i As Integer = 0
While i < animals.Length AndAlso i < fruits.Length
line = String.Format("{0,-20}{1,-20}" & vbLf, animals(i), fruits(i))
sb.Append(line)
i += 1
End While
System.IO.File.WriteAllText(fileName, sb.ToString())