Help understanding grandfathers service record - starting 78th fld reg

I noted that home means home, but I have also seen that in 1939 the reg went to France...as a home forces regiment. So I don’t know how they would record that. If he is with the 78th since 1938 and the record shows the unit went to France and returned from dunkirk does that mean he was not there and at home or he was there as part of his regiment in “home forces” under 52nd div. ?

see - A Short History

I don’t see any mention of France etc. on the record. I’ll update when I get a copy of actual records but from what I saw of them there was no other record.