There are many games available to help you practice your tables:
From Transum Software comes Flash tables which will present you with random questions from your chosen tables and then show the answer at the speed you select. Also from Transum, see this great Tables Collection which has several activities to try.
Try this Tables Test from tablestest.com which you can play at different levels.
BBC Skillswise though written for adults has some useful activities for students.
For a real challenge try a Find the Factors puzzle from Iva Sallay.
Sumdog has many numeracy games including tables.