Sure. String.Split() is going to be your friend here. It will split the
string into an array of strings - for your example, splitting on <tab> would
give you an array of strings { "Field1", "Field2", "...","Field20"}
Here's an example that will read in each line, then print out each field on
it's own line:
------------------------------------
Imports System.IO
Module Module1
Sub Main()
Dim reader As New StreamReader("c:\filename.txt")
Dim oneLine As String = reader.ReadLine()
While Not oneLine Is Nothing
Dim vals() As String = oneLine.Split(vbTab)
'Do something interesting with the array of strings
Dim s As String
For Each s In vals
Console.WriteLine(s)
Next
oneLine = reader.ReadLine()
End While
End Sub
End Module