The textures for bells, conduits, and the book on enchanting tables have a variable amount of padding applied. However, padding is only relevant for block textures, and for block entities does nothing but bloat the atlas for no gain, pointlessly increasing graphical memory usage and harming tiling efficiency.
Much like MC-303743, this is an easy enough fix: the bell, conduit and book textures just need to be split from the blocks atlas and moved to their own, dedicated atlas that does not use a variable padding distance. It may even be a good idea to merge existing block entity atlases into this new atlas (beds, chests, shulker boxes, signs) - this would mean there are less atlases to create at resource loading time, and several types of block entity could be done in a single draw call. A proof of concept can be seen here in the Vibrant Vanguard server: https://discord.com/channels/1362331987666403328/1362518197902905618/1427396220589965363
Thank you for your report!
After consideration, the issue is being closed as Won't Fix.
Please note that this is not the same as Working as Intended, as this bug report correctly describes behavior in the game that might not be the intended or desirable behavior, but it will not be fixed right now. Sometimes, this is because the issue reported is minor and/or impossible to change without large architectural changes to the code base.
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