Yeah - walking solidly for an hour is going to max out at about 250 calories (unless you start hill walking or adding extra weight). A latte (not even a Starbucks-y sugary one) is about the same amount of calories.
You should walk. It’s really good for you. But skipping the coffee break at the end will have more of an impact on your weight than the walk itself.
Walking might be a better choice but no matter what you do you still need to control the intake of calories.