See screenshot:
http://i.imgur.com/y5h3bfh.jpg
If your screen is small enough, you can't save translations because those "suggested variables" are hiding the "save changes" button. They are moving (floating) when you change your screen size. My suggestion is to make another box for those variables.
| Subject | Author | Repo | Branch | Lines +/- | |
|---|---|---|---|---|---|
| Wrap insertables inside textarea | Nikerabbit | mediawiki/extensions/Translate | master | +17 -0 |
When there are many suggestions, you can collapse those not fitting one line into a more menu (e.g., a "..." labelled button) that acts as a menu for the rest.
Another option may be to show only the elements that fit in a line as long as they are not used in the message. In that way, as you add elements, new ones are available to add. This presents limitations compared to the approach above when the element you try to add is not there or you want to add to twice.
Change 278259 had a related patch set uploaded (by Nikerabbit):
Wrap insertables inside textarea