Google AdWords KeyWord - Find Best Tag

In its home page, go to Tools and Analyis tab and select Keyword Tool.
Put your word or phrase on the form. In want to know which keyword is most searched, tablet or slate. Below, I put tablet. Then I choose the Category, Computer & Consumer Electronics. Then, I type the captcha words only once.
For the tablet keyword, the result is around 30 million global monthly searches.
For the slate keyword, the result is around 3 million only. Which validates my assumption that tablet is more common search keyword term than slate.
You can also, find combination of additional keyword usually added to the main search term below of the results and its number of global monthly searches.