Novice isn't overly big - about 90 I'd say. I wouldn't go back to tatts though - absolutely crazy last time I went which was a few years ago- sending them out at 20 sec intervals and they did'nt even have time to run singles class. I did pairs with my sister and we picked up about 10 people on the way around who all followed me for a lead!!
I'd much rather go to Shillelagh hunter trials in Coolboy on 17th (has pre novice class) or Punchestown on the 16th (novice would be closer to 80-85 there but it does get very busy so can be a long day but there's lots of space) - both which are lovely courses and great as a first hunter trial of the season.
starts at 10.00 with Open singles, Open Pairs, Novice Pairs, Novice Singles (time permitting). I gather the Open will be about 1metre with some fences possibly up to 1.10 and Novice 90cm.