First of all it depends on the file type of the movies.
And if the tv can decode the files.
Most movies if in Divx Xvid or Mpeg four require codecs or hardware decoding of the files it is being played on to run them.
If it is the case.
The second is the tv may not be able to use the file system created on the hard drive.
Most will read Fat 32, Ntfs, Or Gpt formatted drives with a file system.
But you have to check if the tv will support the Mac based file system formatting.
Based on the make and tv model number. And what video codecs it can play.