Edit the tables fields and turn off the nullable flag?. This what you are after?.

There is no such option for the Data Editor.

But as Pierce suggested you can use a Nullable flag.
Most probably SQLite will not allow you to change the Nullable flag when data is in the table.
So you can set it for a new table before adding/importing records to this table.

Nieko Baarda
Suggestions from (person) chat-bot Paradigma solved my question.
Fields where checked (v) for Nullable before import csv file.
Changed flag by uncheck Nullable. Than import csv file and empty fields show empty. Thanks for help.

Thanks for help.

If flag of fields unchecked Nullable before import csv file, empty fields show empty.

I need to do this by first create fields that exist in the csv file.

The first row of my csv file contains the field names.

So I need, when not creating table and fields by myself, in the Import Wizard the option setting Nullable / NoNullable for fields of the csv file, if importing a table (fields and values).
See attachment:
valentina_import_table_auto_check_nullable.jpg

Do I something wrong when importing in the Import Wizard a table (fields and values) without first creating the table and the fields ?