How to enlarge photos before importing?

I am using Lightroom version 4.0 (not Classic, although maybe I need to switch to it). When I insert my SD card I am faced with either uploading all my photos (could be thousands) or try to choose the sharpest and most inersting frames based off a thumbnail. By now there has to be a way to enlarge the image before importing. I read that hitting the "e" key will complete the action. I have tried selecting a photo and hitting "e" while combined with various command keys (MacBook Pro) and still have not figuired out how to enlarge the thumbnails before importing.