I can't tell you where to do it.. But I can tell you mine has a different standard width
Try changing your screen resolution or even something like the font size settings in Windows and see if that has any effect on it..
What version of Inventor do you have?
Mine looks just like yannicks in 2019
Hi! I think the default column width is hard coded. But, it does adjust based on the content. I have seen some users adding some custom iProperties in the template files. Then the column width would be adjusted accordingly.
Many thanks!