Does a tablet replace a laptop needed openoffice work?

I just need a laptop to write something in openoffice 4,1,2. Are there any special programs on the tablet?

Depends on the operating system. On a Windows tablet, you can install Open or LibreOffice as usual. For Android there's not, but some other office suites, usually with less features.

It makes sense to need an external keyboard for writing.

I would prefer a desktop PC / laptop for Office.

Yes, there's an app open office for android tablet - is almost the same as the normal open off. I also install. Mfg.m.