When setting a texture to 'Sprite Mode: Multiple' the format that it is stored in an Asset bundle has changed since Unity versions >= 5.3. Prior to 5.3 the asset bundle would include all of the sub-textures (top left, top right, bottom left and bottom right) but not the whole texture. Since 5.3 the asset bundle includes all the sub-textures as well as the whole texture.

This is leading to an increased memory size for asset bundles with LZMA compression.

See information on how to reproduce below with the initial bug report.