How often are you in a crowded area and you need something for your child to do? Maybe to help them regulate their emotions and keep them occupied while waiting for a meal to arrive? I know that electronics are not always the answer as some children struggle with them and sometimes they simply are not charged, so what do you do? You go old school, keep a blank notepad and writing utensil on hand.
If you are prepared to be waiting at the table when going out to eat then you are more likely to be successful. Be ready with something to write/draw on. Not only does it give them something to think about (rather than the food that has not yet arrived) but it also gives their muscles something to do. This will help them to regulate their emotions. Busy hands also keep those same hands from creating further havoc! They are less likely to be doing something they are not allowed (punch and pinch). In fact, if you have a child that uses their hands to pinch, drawing and writing will give their hands that same feeling, filling their need.
The same notebook can also be used to tear up. Some children find comfort in the sound, scent and feel of tearing paper. If you bring paper to fill this need, to allow it, then your child is less likely to try and tear up the place mat at the table.
One last thing is that the paper and pen can also be a way to attach with your child. You can be waiting for an appointment or for a meal to arrive at your table and play a game of nought and crosses (tic tac toe), or see if your child can copy the simple drawing you have made, then change it for them to draw something for you to copy.
Sometimes the simple tools are the easiest to keep on hand and can also give you the most benefit. Paper and pen are one of those items, easy to keep with you, low cost, and valuable when you need a tool to help your child regulate their emotions.