MySQL table design / architecture, table is too big
Well first there is no way that all of this should ever be in one table. You need related tables for information such as Assignee and Inventor. Please read about normalization. 

But in reality are you sure that mysql is the way to go for this since you seem mostly to want to search on data that is not always in the same form. Personally, for this type of thing I would look at NoSQL databases for the text parts in conjuction with a relational database for the data that is easy to describe and determine the size of.