It's almost never a good idea to make one big test. Either build a framework test that calls all the other ones with particular data or in a particular order or use the Test Items feature above, or both!
You can use test items or you can build composite keyword tests out of multiple building blocks. Simply drag and drop your building blocks into a new keyword test and you should be good to go. Really... that easy.
And then, as @Marsha_R mentioned, build out a framework or use Test Items to call your composite tests in the intended order.
Why automate? I do automated testing because there's only so much a human being can do and remain healthy. Sleep is a requirement. So, while people sleep, automation that I create does what I've described above in order to make sure that nothing gets past the final defense of the testing group. I love good food, good books, good friends, and good fun.