Where can I get a SQL Server Trace Dataset?
Pattern analysis would be entirely dependent on workload.

Every workload is different. Not just differences between transactional (OLTP) and analytics (OLAP), but even a dozen OLTP applications will produce entirely different patterns.

If you want to build a synthetic one, capture a trace while benchmark tests run. You can start with Benchmark Factory or HammerDB as mentioned in this Stack answer.