You can create versatile PDF forms using Adobe LiveCycle Designer. If your forms contain drop-down lists, you can either type all the values, or bring a large chunk of values from MS Excel or plain text formats. Watch the video to see how.
This is especially helpful for large dataset, where it is practically impossible to type them. Although this video uses Designer 10 as part of Adobe LiveCycle ES3, this works in some other versions of Designer too.
For more information see the following links:
A complete list of Adobe LiveCycle Designer ES3 documentation.
More information about the Drop-down lists in Designer Help.
Check out the Designer FAQ for more Q&A.