You can have as many things as you like on any circuit. The total that can run at the same time will be limited by the 15amp fuse.
So, is is safe? Yes
Is it a good design? Maybe not. It depends on the maximum load that could be experienced.
Personally, while the wiring is all exposed, I would get an electrician to check out that circuit and see if a larger fuse could be used for that circuit. It would mean you won't be short of capacity in the kitchen in a years time!