There’s no black and white answer as it depends what sort of industry you are in and the risks associated in the types of work that you do.
In a basic first aid kit you should have:
Most workplaces will also have a separate specialised burns kits and often a defibrillator.
Again it depends really on the type of work you are in and the amount of people that you work with. Ideally any workplace should have at least two appointed first aiders.