Without knowing what you'd like to buy, or to experience, it's impossible to answer your question.
As an example of a good way to save money, you might want to buy a year's membership of the Gourmet Society. It normally costs £69.95 but the Society is currently offering it at £44.95. However you can get it by using just £10 of your vouchers. You'll then get 25% of all food and drink, at loads of participating restaurants across the country, for a whole year. (Many places even give '2 for 1' on meals, instead of the 25% off).
http://www.gourmetsociety.co.uk/individ.php
and
http://www.tesco.com/...ips*4294964852|Dining
Otherwise, check out the links here, to see what interests you and offers good value for money. (For example, every fiver of your Clubcard vouchers will give you £15 towards a Butlins holiday. Or you could subscribe to 12 issues of Computer Shopper for just £20 instead of buying them separately for a total of £59.40):
http://www.tesco.com/clubcard/deals/
Chris