[Quoth]

Why do you keep pasting INSERT commands?

I think you need to study how SQL works and ask SQL questions on some suitable forum. This is not a Kobo issue, but SQL issue.

I can clearly see what davidfor is writing if I use "DB Browser for SQLite" (which also lets me edit and export), but I was using SQL before Sony, Kindle or Kobo ereaders existed.

The Table definitions show the column definitions without the data.
Data browsing shows the rows of an instance of a table. They have the actual data.
A table is a little tiny bit like a spreadsheet.
A database is one or more tables with usually some sort of interconnectedness.
Then there are indexes. Advanced databases have constraints, triggers and stored procedures.
But davidfor has been very patient and I'm not going to teach SQL here.

The difference between SQLite and an SQL Server is that the SQLite is simply a file and thus single user. An SQL server hides how the tables are stored and may use a separate file internally for each kind of thing. It's usually able to be multiuser.
A Kobo or Calibre doesn't need the overhead of an SQL server, so SQLite is used. Always work on a copy of the Kobo file. Unless you are writing an application (like Calibre) that modifies the Kobo database you don't want at all ever to use the actual file on the Kobo, but a copy on your computer.