Django Admin to Access all Database Tables

I have many csv files which I need to use them in my Django App and also edit their values by admin.this is what I tried and failed :
In my Django App,I have 2 models for example "City" and "Country" and a sqlite3 database for example testDB.
I registered my 2 models in admin.py file so that admin can add/edit/remove City and Country records.
But in that database(testDB), I have also other tables which created using sqlite commands(create table <table_name>) and I don't have models for those[because thos tables created from a csv file].
But I want admin to have access the 3rd table(which is not created by django but sqlite shell command), in admin panel just like my two models.
Is there a way to do that???? If not, what should I do to solve my problem described in first 2 lines?