MTG-Tabletop-Simulator-Deck-Import-Tool

Use pip install -r requirements.txt
Then run the script with Python 3.x
Click on the Browse button and navigate to the "Deck.txt" you downloaded.
Once you've selected the deck, you can click Import Deck and your custom deck will be imported as an object in Tabletop Simulator.
With the object created, in game, you can click Objects at the top of the screen, choose Saved Objects, and then select your deck by name.