Compress Video
If you want to compress video to smaller size, you can use mac application Quick time player to export it as a smaller resolution ratio one, but the format is mov.
Or you can use some online tool to compress video such as
https://www.flexclip.com/cn/tools/compress-video/
Scale 3D model to make it smaller or bigger
If you want to scale 3D model and not care about scale center by tool quickly, you can use paraview’s filter cell size to do it. Change parameter Scale in Transforming of CellSize.