Playback for .AVI may be more trouble than it's worth. AVI after all is just a container which can hold many different codecs. You really should consider converting your video to MPEG-4 compliant video. Just about any device that plays back video will play back a standard MPEG-4.
If that is not an option... consider a DLNA certified tablet
If that is not an option... consider a DLNA certified tablet