'S í a' rince ar an mbord
Leis an phoc ar buile

Just a few corrections, con permesso:

In Munster Irish, the last line would be " leis an 'bPoc ar buile'" — which is a well-known Munster song. (In Donegal, instead of an urú they put a séimhiú after compound prepositions).

And the translation should be: "And she dancing on the table to the 'Poc ar buile'".

Also "Is bean a ra, is i ar fhaga" doesn't make any sense, and I think it has been mis-heard.

Tapaidh leibh