If you can afford some private tuition then this lot
http://www.kumon.co.uk/ have a good reputation.
With times tables though it's really just about repetition. That's the way I learned them and no doubt a few others of a certain age on here. I know 7x9 is 63 and 9x12 is 108 without thinking. I don't need to know why; I just need to know it is.
Yet when my daughter (who has an A in A-Level Maths) did her times tables, they were taught to memorise the result only. So for the 2 times table it was 2, 4, 6, 8, etc. So if she needed to work out 2x6 she had to count 2, 4, 6, 8, 10, 12. and that was at a very good primary school. To me that's completely stupid.
Learning things parrot-fashion may be completely at odds with modern learning methods, where it's seemingly more important for kids to "express" themselves than actually learn facts, but it certainly works for times tables.