handling csv data with a custom post type

Each post in the posts table has a field post_content_filtered. It can take the same value as post_content (longtext) and it is available without a meta query.

On the other hand … you could create a custom table and import the CSV as regular table content. In MySQL that’s easy with LOAD DATA INFILE. And then you could create a nice interface to edit the data, you can search specific fields … and export everything as CSV.