Reviving blackwood bench tops

Hi all .
I am a new member here and looking for some advise on reviving a second hand black wood bench top that iv recently purchased ,I'm not sure what its finished in , seems to be a very hard and thick coating , there's quiet a few scratches and dents from the move which im not to concerned about as it adds to the character , but it has a lot of fine scratches which i feel need to be removed by sanding ? Is it as simple as lightly sanding back and reapplying a new finish ? If so what would be a recommended coating ?

Thanks :)