Multiplication tables are the basis for a huge amount of maths, ranging from simple sums to division and cancelling fractions.
Use these sheets as timed practice, with the aim of getting a quicker time for each and, of course, all correct. A limit on time can be given. A good 11 year old would need 2 minutes or less; most children would need between 10 to 15 minutes to begin with.
The grids can be approached in a variety of ways; completing in strict order or picking out the ones you know (such as 1x and 10x) first and then filling the gaps.
There are lots more like this at mathsphere.co.uk