The right way (import)
The commercial version of Maltego has support for visualizing spreadsheets. You can also use this to simple import a single column of data. Let's say you want to import only names. Then it goes a little like so:
Click on the picture above to see what's actually going on. Importing data this way seems like a lot of effort, but it's really useful. Why? Because it allows you to import multiple columns and make a real graph. Imagine you had phone numbers as well - then you could easily end up with this (skipping the boring bits):
You can "chain" any number of nodes together - in this case we've only used two.
The quick way
You can import entities into Maltego (also in the community edition) by copy and pasting it from text. Usually Maltego does a great job of figuring out what it is that you are pasting - but you can force the entity type by pre-pending it in the actual text. Check this out:
Of course, this does not give you the ability to actually create graphs - it just imports the nodes. But...wait..that's what you wanted right?