Yes. A Netherlands passport holder normally needs an Ordinary Visa for a safari, Zanzibar holiday, Kilimanjaro trip or other genuine tourism visit. Dutch citizens are eligible for both the online and visa-on-arrival facilities.
The correct category for a Dutch leisure traveller is usually the Ordinary Visa. That route fits a wildlife safari, beach stay, family or friend visit and other permitted short purposes that do not involve Tanzanian employment. Eligibility follows the passport being used, not residence in the Netherlands, possession of an EU identity card or the airport from which the traveller departs.
Tanzania Immigration lists the Netherlands among nationalities that can obtain a visa online or on arrival and recommends the online platform. Applying before departure moves the form, upload and payment work away from the immigration hall. It also gives the traveller time to replace an unreadable passport image or correct a route that accidentally shows two first hotels.
Official guidance describes the Ordinary Visa as valid for up to 90 days, but the grant notice and border decision determine the actual permission. Tourism does not authorise paid work, local employment or an extended course. Applicants should choose another immigration route when the real activity falls outside a visitor holiday.