Hmake
From Scriptwiki
Creates a new hash table with N slots.
/hmake -s <name> [N]
A hash table can store an unlimited number of items regardless of the N you choose, however the bigger N is, the faster it will work, depending on the number of items stored. If you e.g. want to save about 1000 items, using N = 100 is sufficient. The default N, that will be used if you dont specify one yourself, is 100.
Using the -s switch makes the command disply the result (e.g. * Made hash table 'moo' (100))
Note that if a hashtable with the given name already exists, it wont make a new one.
Example
hmake users
It will just make a new hashtable called users.