what is the maximum size of a record in a table (MySQL database)? and how can it be increased using phpMyAdmin?

what is the maximum size of a record in a table (MySQL database)? and how
can it be increased using phpMyAdmin?

I am managing a website and i got the following issue:
I cannot insert more than 64 KB of content in a record inside a database
table (MySQL database).
How can i increase the size of that specific record so that it can accept
more content?
Cheers!!