Along with reading and writing, learning your times tables is paramount. Some children take to it naturally others will struggle. It is rather like learning to walk before you can run. Running builds upon what you aready know about walking regarding balance and movement. Like times tables, from the very onset of learning multiplcation and division are a thorough part of mathematics teaching and learning. The ability to do one undoubtedly affects how you do the other - it is impossible to learn long multiplication if you don't understand short multiplication and how can you possibly undertake long division without knowing your tables?
Essentially, learning your times tables prepares you for the harder tasks in maths - more confidence, speed and accuracy will make further learning and challenges far less daunting.
As well as in school it becomes part of our everyday lives - when baking, shopping, discounts etc. It will be far easier for someone who is able to quickly recall mulitilpication facts and will inevitably save time.