Hello there iMavy,
Thanks for posting here on the Apple Support Communities! This is a place where other Apple users can submit questions or respond to others to help lend a hand. Let's take a closer look as we do our best to provide some additional insight.
We understand you're getting a low storage alert while trying to AirDrop some files to your iPad. To get started, are you trying to AirDrop 6x separate files at 8GB each, or just 2x files, one being 6GB and the other being 8GB? The reason we ask is 6GBx8GB=48GB. Where as 128GB minus 84.8GB=43.2GB, so that would not be enough space in that case.
In the meantime, does the same thing happen if you test with smaller files or documents? Otherwise, try making more space: How to check the storage on your iPhone, iPad, and iPod touch
We hope this helps get you pointed in the right direction.
Take care.