That is map data attached to the polyline. What is your goal? Are you trying to write a program to work with map data? If so, what programming language do you use? Map 3D has a lot of tools built in.
I don't see that Autodesk supports LDT anymore. I use Map 3D and others here use Civil 3D, which is built upon Map 3D. For better help, let us know what you are trying to do.