Various things; attacking concentrations of ‘invasion’ barges in Channel ports, attacking German targets such as oil installations, the Dortmund-Ems canal, Berlin etc. Blenheim squadrons were tasked with attacking Luftwaffe airfields in occupied territories, often at great cost.
Thoroughly enjoyed it, as has already been said; this was a mainstream programme aimed at the general public and I think that the general balance of history, veterans, modern day recreation and indeed, celebs, was spot on.