For uploaded files in episerver, I see that in the code object, it has properties of Title and keywords, but I can't enter this information via the edit file summary screen in edit mode.
How can I do this?
To enter values to Metadata through "edit file summary" in the file manager you'll need to change your filesummary.config file as that describes what will be shown in the file manager.
If you want to read more about filesummary.config you can look at this forumthread, especially the answers from Linus Ekström and Fredrik Haglund.
Link to forumthread: