Error: 1146 Table 'bighead3_wiki.objectcache' doesn't exist (localhost)
have you checked what the error message tells you? The DB you use should be called "bighead3_wiki", right? Do you have a table called "objectcache" in that DB?
However, you should have one! If it is missing, try to run the Upgrade Script to create it!
As last resort, try creating it manually from the tables script: 
It is correct that manually adding the table should add it to the database, but I am not sure, if this solves your real problem.
It would be interesting to know, why this table is actually missing. If your database is corrupted at one place already, there might well be other problems with it as well. If it was my wiki, I would take an unbroken backup and continue with that.