We had lunch in La Rochelle the day we were there. We sat outdoors at one of the cafés on the quai Duperré at the north end of the Vieux Port. The line of buildings in the photo below shows the buildings along the quai, which all have cafés with terrasses (outdoor seating) at street level. The tower is again the clocher de l'église Saint-Sauveur.
Below is a closer shot of all the sidewalk cafés. The one we found that would accommodate us and the dog is called Les Régates, on the left in the photo. We got a table on the edge of the terrasse where the dog wouldn't be in anybody's way.
You can see how low the tide was, and how sunny the skies were, that day. It was all very pleasant. We ordered two plate-size pizzas, as we often do when we are out at lunchtime.