I'm not an expert in database management, but to me that number is too high for a database column or tables.
Have you ever heard about Dabatase Normalization? Simply, it's a concept of separating columns into tables and make relations to it. It's useful to avoid redundancy and dependency. It also will free your databases from some anomalies (deletion, update and insertion anomalies).
A character having a table just for its items is completely unnecessary. What if there's a new character? Making the same table (with only different names) over and over again is obviously redundant.
I'm wondering how could your database have that many tables and column. Can you please export your database and upload it here? That way I can analyze it and, if possible, make it more simple and effective. Trying to tweak something I can't see is hard.
The row number is fine if the game is really big, but not for column and tables.