I am unaware of any bulk way to transfer documents. These are the closest methods I know of.
If you have iCloud, the easiest way is to open iCloud.com on your computer, then drag the files to the iWorks app in the Pages tab. You can select and drag multiple files this way. Provided you've set up Pages on the iPad to sync in iCloud the documents will download to the iPad automatically the next time you open the app. You will still have to open each document on the iPad to finish the conversion process. Big documents may require some extra patience.
The other options require more steps, but might be faster.
Using
iTunes File Sharing you can copy the files to the iPad using iTunes on the computer. When you go to the iPad you have to create a new document and import from iTunes. Tedious if you had a lot of documents. Once you've imported them all you can go back to File Sharing and delete the documents from the iPad; unless you'd like to leave them there as a kind of handy template. As long as there are there you can reimport them for a fresh unedited document as many times as you like.
Any WebDAV cloud service will work. You upload the files to your cloud service, then use the WebDAV option to create a new document. Box.com works for this. You can also use DropBox indirectly with SMEStorage's CloudDAV service.
And, of course, you can email them to yourself and use the Open In feature to copy them to Pages.
Pages on the iPad automatically converts from the full OSX format to the more limited iOS format. It will strip what can not be converted and present you with a dialog box describing what has been done.
