Is there an equivalant to Environment.NewLine in DotNet for a Tab character?
Short answer is: no, tab does not change between platforms as newline might, so there is no need for one.
Long answer is: technically, yes, you could use the one provided by VB in the Microsoft.VisualBasic.dll. I think it's Microsoft.VisualBasic.Constants.vbTab, but there's no good reason to use it in C# as I said above.