Trafford,
so far you missed an essential piece in the picture: MySQL Workbench is 2 tools in one:
1) A modeling part, for designing your database.
2) The SQL IDE for working with your database(s) and managing your server(s).
The "Inserts" tab in the table editor in modeling is a special area to take some test data that is applied when synchronizing your model. It is not meant to keep a large amount of data. Modeling is about design and that should be done before you fill in your data, as applying design changes can easily lead to data loss (e.g. when dropping a column).
What you really want is the SQL IDE, where you connect to your server and work with your data. You can import CSV data into a table (see context menu in the schema tree) and other work. There are overlay icons in the schema sidebar on the left that allow quick access to table data, table editor and table info (respectively the other db objects).
Mike
Mike Lischke, MySQL Developer Tools
Oracle Corporation
MySQL Workbench on Github:
https://github.com/mysql/mysql-workbench
On Twitter:
https://twitter.com/MySQLWorkbench
On Slack: mysqlcommunity.slack.com (#workbench)
Report bugs to
http://bugs.mysql.com
MySQL documentation can be found here:
http://dev.mysql.com/doc/refman/8.0/en/