Sounds about right. Those two "2 Bytes for Fixed length" and "2 Bytes for all columns" are storing information about the offsets within the data portion for the fixed length columns (the first) and the variable-length columns (the second)
Gail Shaw
Microsoft Certified Master: SQL Server, MVP, M.Sc (Comp Sci)
SQL In The Wild: Discussions on DB performance with occasional diversions into recoverability