Here is a link to the details of the trade deal:
UK AHDB article
As I read the article , Imports of Australian Beef will lose the 20% Tariff and become subject to a rising annual upper quota limits over 10 years.
UK imports 270,000 tonnes of Beef , mainly from the EU and Ireland, current figures are Australian Beef imports are only 2500-3000 tonnes. Over 10 years the Australian beef may account for 170,000 tonnes of imports, the tariff -free quota is for 170,000 tonnes.
Potentially EU beef imports will fall to 100,000 tonnes.
If Australia becomes the dominant player then prices may well fall below EU imported beef
Australian beef is typically a premium product., and Austrailia is an efficient low-cost producer, As a consequence t of the deal we may be enjoying tasty steaks for the price of bland mince.
The peculiar thinking of the EU, who for the purposes of the quota and tariff system, equated the weight of the edible meat with the weight of the animal, was probably to force us to accept the lower quality meat cuts and to force everyone to pay tariff on the unwanted offal