TotLM is a mini expansion to HoW which adds a huge new area, with some new items and monsters and some minor stuff like new portraits and so on.
Most importantly it contains the latest patch (not found anywhere else as standalone) which fixes quite a few problem...
It is free to download and as far as I know was made because many complained that HoW expansionwas too small.
Info and download here:
http://www.planetbaldursgate.com/iwd/info/luremaster/