Is there a way to list the largest files and folders in Time Machine backups?
Yes - you can find large files in many ways.

In the finder search field type size:>9000 and add a size field if you wish in the list view to sort descending. Add zeroes to the number to get less results back for your file sizes.

This doesn't work well for network backups in my experience due to lag or incomplete spotlight databases. If that doesn't work, get a tool made to analyze Time Machine backups like BackupLoupe. It is crafted specifically to efficiently scan time machine backup drives and network volumes. It creates a comprehensive backup database of all the files and revisions that would make your size query a snap.


http://www.soma-zone.com/BackupLoupe/


Install the app
Let it index one or more intervals
Use the app's find window to sort on size after setting the search criteria as follows: Type is directory and match type of none of the following is true





It also helps to reveal the files in Finder so you could decide to remove that file across backups or just to delete that interval entirely.


Remove unnecessary backups from TimeMachine to get space
How can I manually delete old backups to free space for Time Machine?


Since Time Machine stores each backup in folders, you could unleash any other tool (DaisyDisk, Grand Perspective, WhatSize or other) on the backup, but they don't know how to interpret hard links and may take days or months to make a picture that doesn't represent the actual storage allocations. 

BackupLoupe is smarter than the existing tools and doesn't double count hard linked files. It also runs in the background if you wish. Lastly, it reads a database file summarizing the backups so the results are near instantaneous and you don't even need the backup drive mounted to do the reporting.