It was a long time ago for me now, but I learned the times tables (using your example) as "three ones'r three, three twos'r six, three three's'r nine" etc. Seems like it's just the addition of a single "zrr" syllable after both numbers to me, and to me that seems easier to say than e.g. "3 2 6", maybe just because it's an automatic reflex to add the extra sound and not adding it makes it seem just a stream of numbers out of context.