Creating extra columns in one table vs creating a new table with foreign key

I have a SQLite database with a table with 11 columns, including 8 columns as Text with very long strings. I need to add 8 more Text columns which may or may not get long string values.

So I'm wondering whether I should add those extra 8 columns to the current table or create a new table containing a foreign key?

Which way is better in case I want to use some queries to search data in my database?

Thank you.