Hi chumlee!! Hope you are doing well!! Abbreviation table is an important of note making. You get marks for each and everything. But abbreviation table should not be very long. There should be maximum 8-10 abbreviations. If you write more than that, you may loose marks too. It will depend on the examiner who will check the paper. You may get more marks for many abbreviations or you can loose the marks too.

Yes abbreviations are a very important part of Note Making in English and considering that yes you can get some marks for that but it will depend on what abbreviations you made and how good were they utilized because in many cases people just make any kind of abbreviations to make it look good. So it will all come down to how good your abbreviations and their usage was