The office for National Statistics (ONS) 2018 Pink Book for the British Balance of Payments in 2017 is here: UK Balance of Payments, The Pink Book 2018
The Office for National Statistics (ONS) 2016 Pink Book for the British Balance of Payments in 2015 is here: Pink Book 2016
The contrast between the huge trade deficit on EU trade and the trade surplus on non-EU trade is large.
The latest WTO report for tariffs between countries (including EU) is here: tariff_profiles15_e (1)
See page 77 of the WTO report on tariffs for the tariffs that apply to the EU. On a trade-weighted basis the average EU tariff is only 3.6% and falls to 2.3% when agricultural products are stripped out.