I think you've misunderstood how the Hyperlinks' Add method should be used.
The first parameter (the Anchor parameter) represents the object that you want associated with a hyperlink. This can be an object (like a graphic) but is more commonly a range of text, as I think is probably the case in your example.
Also, you've accessed the Hyperlinks collection by accessing the Range property of a Table object. This means that you're only accessing those Hyperlinks that exist within the table, and is irrelevant to your needs. It would clearer to access the Hyperlinks collection of the entire document.
So, assuming you want to insert a textual hyperlink into the 2nd cell on row 2 of your table, you might use something like the following:
Code:
object missing = System.Reflection.Missing.Value;
string hyperlinkAddress = "http://www.google.com";
// myTable should be a valid Microsoft.Office.Interop.Word.Table object
object targetRange = myTable.Cell(2, 2).Range;
// wordDoc should be a valid Microsoft.Office.Interop.Word.Document object
wordDoc.Hyperlinks.Add(targetRange, ref hyperlinkAddress, ref missing, ref missing, ref missing, ref missing);