No need to book a table for supper. There are plenty of tables in the restaurant and bar areas.
There is also a popular and very good for supper pub next door with lots of tables.
Hope this helps.
You can plan any number of local activities (you know your child best so will know what will keep them happy), the great thing about this kind of area is that almost every pub, restaurant and service station has a stand full of leaflets for local attractions, so you can grab a load and decide based on the weather.
Sorry can't answer this as we didn't stay there we only ate there one evening. But I do know they have their own website with the prices there. Hope Cove itself is lovely you will enjoy it there with your children. Best wishes Kathryn