To copy filenames, go to File > File Names > Copy to Clipboard:
https://winscp.net/eng/docs/filenames#file_name

If you need sizes (and other attributes), then it is more difficult. Do you have shell access? (you mentioned both SCP and FTP, what are two different things, so I'm not sure which one are you actually using). With shell access, you can execute ls command on the server
https://winscp.net/eng/docs/remote_command

Another way is to implement a custom command/extension to produce a listing in any format you need. But that involves coding.

Good afternoon, I am not an experienced WinSCP user and please pardon the simplicity of my question.
We currently use SCP to connect to an FTP site where we create visual assets. I am curious if there is an easy way to dump the directory contents (Filename, date, size) to a text file to be imported to Excel. Traditionally, I would do DIR > DirectoryContents.txt and then import the text file. Is there anything similar where I could do an entire tree structure into a text file?