Currently, when using smaller lists of smallish value maps, the admin screen works mostly fine.
However, if you have a couple of large value maps (like HTTP response codes and such) or you have a lot of them, the amount of scrolling required becomes a pain.
Also, if you have value maps that are larger then the hight of the browser window, navigation without getting lost is difficult.

I propose the screen is to be redesigned to work around these problems. I would like to see it a bit like the template screen.

In the left column there would be the name of the value map, with a mention of how many mapping there are defined. Clicking here will bring you to the value map configuration.
It would be cool to have a right column that shows which templates/hosts actually use the value maps (like links in templates). Clicking the host/template brings you to the item config screen for that host. Perhaps we can filter on the use of the value map there. This layout will also allow for a consistent view when ZBXNEXT-1679 gets implemented.

Using a filter to only show value maps that match a certain string might also be a neat idea.