We heard from many manufactures who follow the practice of a general tolerance table. This is specified in the ISO 2768 standard.
Now MBD18 can insert a customized tolerance table as shown below. This table is for visual look-ups per the sizes and tolerance class, similar to the 2D drawing practices.
Give it a try:)
Thanks,
-Oboe
SolidworksSolidworks 2018 Beta