How to save a bookmarklet link when using safari?
With only iPad and safari: open the link provided. Now, click on one bookmarklet suitable for you, and open it.

On the new window, in the upper part, there is one square with an up arrow, click on that and from the popup menu opened, choose "Add bookmark" and save it to your choice (a good one is Favorites page).

When need to translate a page, click first on the big " + ", choose the "Google Translate" icon and open it. Then copy/paste the address from your page to Google translate page. 

Keep in mind that on Google Translate page, you can choose another "From" or "To" page, by clicking on the respective buttons.