Bhí a fhios agam .... I knew the name, King, to be on him as well as they, but I knew also of what is associated with it, and, with that, I was not surprised (i.e I took no interest) him to arrive in the form he left (i.e. he had brought nothing back with him)
agus gan sé phunt déag a thabhairt ... and not to give (spend) £16 on two barrels of ale for the rif-raf of this place.

Presumably Tomás knows that Kings take and don't give!!
Gramaisc is a great term of contempt meaning rabble or mob.