Here is my modification of the method, which is much more shorter, using LINQ to to retrieve the server variables:
Dim d As IEnumerable(Of System.Collections.Generic.KeyValuePair(Of String, String)) = _
From c In System.Web.HttpContext.Current.Request.ServerVariables _
Let s = System.Web.HttpContext.Current.Request.ServerVariables(c) _
Select New System.Collections.Generic.KeyValuePair(Of String, String)(c, s)
After that, bind it to GridView:
GridView1.DataSource = d
GridView1.Bind()
This will give you all the values from Request.ServerVariables.
Request.ServerVariables, Another LINQ way | My Code Snippet