I read this: Importing a CSV file into a sqlite3 database table using Python
and it seems that everyone suggests using line-by-line reading instead of using bulk .im
Sqlite can do tens of thousands of inserts per second, just make sure to do all of them in a single transaction by surrounding the inserts with BEGIN and COMMIT. (executemany() does this automatically.)
As always, don't optimize before you know speed will be a problem. Test the easiest solution first, and only optimize if the speed is unacceptable.