These 2 column headers can be found in replay viewer:
The second column is just a numbering column and it's currently taking half of the size, which makes the file name truncated most of the time. It would be great if the header positions were able to be saved after manually resizing them (e.g. like in replay manager) or better automatically resized - either similar to level manager's top 10 sections after clicking on a level or even automatically resized to fit the text.