I exported a group of pictures yesterday that I wanted to view on my iPad. So, I used Jeffrey's "Export to Picasa Web" plugin which you'll find here: http://regex.info/blog/lightroom-goodies/picasaweb
This allowed me to create a new Picasa album for the selected photos. Over dinner with friends I was then able to share this album on my iPad.
I'm sure there are other ways of accomplishing your goal but this worked for me.
You might want to check out an app called Photosmith. Version 1 allows you to sync images from your iPad to Lightroom. App on the Ipad for sorting etc, and a plugin to import into LR.
Version 2 looks like it will allow bothway transfer, have to admit it is a great tool for me on the road. Download my images (Camera Kit) to my iPad, sort my images, tag etc, then when I get back import the images into LR. Keeps me occupied on long flights and improves my productivity