Hi @Arny,
A warm welcome to the Bunnings Workshop community and thank you for your question.
You can use a simple filler product such as this UNi-PRO 500g Multi Purpose Interior Filler. Just make sure to give it a good mix so it is smooth before application.
Wait for it to dry, then give it a quick sand to smooth it out before painting.
You might like to check out How To Paint A Kitchen Benchtop With Dulux for some guidance on the painting process.
Let me know if you have any further questions.
Jacob
