What is your pulse upon waking before breakfast? 80 seems like a great pulse to settle at for most of the day (are you familiar with Ray Peat? He suggests a pulse of 75-85 is optimal).
A pulse jumping high immediately after a meal is probably common- staying that high for an hour seems a little odd, though sometimes my temp/pulse doesn’t change for 30-45 mins after a meal.
I’ve heard that if you eat something your body doesn’t like, pulse can jump high like that- but if the pulse isn’t dropping too low after that, I probably wouldn’t worry about it right now. If your pulse is generally in the 80s and used to be in the 50s or 60s, I’d say you’re definitely headed in the right direction. That bump up to 100 could just be a temporary thing for now while your body gets used to processing a lot of food after a good meal.
I’ve also heard that people who used to have a low pulse (50s or 60s) and then increase their pulse to 70s or 80s often feel weird at first because they’re not used to the feeling/increase- so it’s normal that it feels strange to you. But you should get used to it after a while– especially since you say you’re feeling good otherwise.