The Method column contains a list of methods in the stack trace of the thread that caused your program to crash. Depending on the platform you may see methods that don't match your source code. This is because platforms such as Windows Native, .NET Framework, Crashpad, Breakpad, macOS, Unity, and Unreal require you to upload symbols for each version you release in order to calculate the correct method names. For more information on how to upload symbols please see the documentation for your platform.
Clicking the > (greater than symbol) in the left-most column will expand the Row Details view.
The Row Details view will display the Create Subkey button that will allow you to create a subkey. Grouping at a different level of the call stack is called subkeying and is useful in cases such as a crash that occurs in a 3rd party library, or when additional stack frames are added by a crash reporter.
When you land on the crash details page, BugSplat starts a debugging session in the background that will calculate additional information about the crash. This additional information includes the call stacks for the non-active threads, register values, loaded modules, and function argument and local variable values. You will see a loading indicator when this information isn't yet available.