It's a comic song. The chorus goes:

Dear Matilda, how I loves ya

And I've found a happy home

With a cowshed and a pig stye

Full of cows and pigs and that reminds me

How's your father? How's your mother

I hope they're fine you know

I send no kisses, I've been eating onions

Yours sincerely, Joe

Hope it rings a bell with someone.