Beside sending the text file from within the data table by email, there are two alternative ways to transfer your data to a computer.
First, you can use iTunes File Sharing. Connect your iPhone with iTunes and select your iPhone from the Devices section on the left side of iTunes. Click the Apps tab and scroll down to the bottom of the page. Under the File Sharing section, you should find Lambert amoung other apps that support File Sharing. After selecting Lambert you should see a file named "LambertData.txt". You can drag and drop or use the Save to... button to copy this file to you local file system.
Second, you can follow these instructions to transfer the data to your computer by using a local (ad-hoc) or a WiFi net.