Is there a reason to use extremely abbreviated table names?
Oracle has had a long standing limit on table names of 30 characters.  I suspect this is a legacy issue based off an original 16 bit environment.
The length of a table name could have some minuscule effect on performance as all the names have to be stored in a data dictionary and also parsed for queries but I don't think you could measure the hit.  

A more important effect of short table names is that it's hard to work with.  I too have to maintain an enterprise database schema with short names.  There is no good reason to have short table names.  Ease of maintenance trumps obfuscation or old DOS habits every time.