We go out a lot - to restaurants, we travel, we hike, etc. and it's always been a bit of a struggle to keep my little ones to sit down quietly, especially at restaurants.
With my first, at some point, we resorted to giving her a phone at restaurants and she'd entertain herself watching Youtube videos (Baby shark, anybody?). It has been very easy and it has provided countless relaxing meals for the adults. But... I've always felt guilty for exposing her to screen time for my own convenience.
Once we had our second child, we've been trying to find other ways of keeping them entertained that wouldn't involve devices, and especially YouTube, which on top of being too addicting, most of the times I don't even know what they are watching. I've started carrying a small toy, or a few crayons and a small sketchbook, which has worked well for the most part.
How to avoid tantrums at restaurants
Until last week, we met up with friends and their little girl and I witnessed the best parenting hack I've seen in a while: they brought in a very large bag filled with coloring books, sticker books, all sorts of markers and crayons and even a portable version of Scrabble. And I mean a LARGE bag and so many options inside!.
The kids were so happy and entertained that I've been doing this every time after that meal.
And yes, I still carry a diaper bag, a stroller, etc. but adding this extra weight is SO worth it! If they get bored with one activity, there are 10 more to choose from, plus they are quite inexpensive and available at Target, Walmart, Drugstores, etc.
In conclusion, the more you expose your children to the things you love to do (for example, eating out or traveling) the more use to the environment they'll get. If you have one bad meal, don't give up - keep insisting, bring tools, make a plan and enjoy!