Hi Tee,
I'm not sure I understand the word "address" in your question, but yes, you can have table files that have more than one character on the right hand side of the equal sign. Such as:
41=A
42=B
43=Ab
44=aB
etc.
Windhex can use a table (file->open table) and should properly display 2 letters for a single hex code. (I have used it when the main character's name is a single byte, for instance.)
You can also have longer hex strings on the left of the equal sign if you want:
A455ED=zz
I would expect most table-handling tools to work ok with that.