I'm a newcomer to ontologies and Protégé, so this question is going to sound simplistic. I have a dataset of people in an Excel sheet (with stats such as height, age, name, etc.), and I have the Protégé 5.0 beta installed on my computer. Would it be possible to import this sheet into Protégé, and then automatically infer relationships/groupings of these people (e.g. age ranges) and create an ontology based on those inferences.
Part of this task can be done with existing tools, such as Populous description here code here.
But the automatic inference of relationships and groupings is a much more complex topic, and while there are a few tools for carrying out ontology based clustering, they are only applicable to very specific and restricted domains. So the answer to the second part of the question is negative; you will have to create the ontology yourself, very likely - or, if possible, import existing ontologies to simplify the task.