When eating or drinking out with people you do not live with (and who are not in your support bubble), you should keep to the wider rules on group sizes: you must only attend these places in groups of up to 6 people.
In all cases, people from different households should ensure they socially distance as much as possible. You should think about where to sit at a table with this in mind – the premises should also take reasonable steps to help you do so in line with COVID-19 Secure guidelines. It remains the case that you do not need to maintain social distancing with those in your support bubble.