Big Data has become a bit of a nebulous term. It’s mostly used by/for business types as a marketing buzzword in my experience. But in principle it just means

Big Data has become a bit of a nebulous term. It’s mostly used by/for business types as a marketing buzzword in my experience. But in principle it just means utilizing data at a scale difficult to handle for traditional tools or approaches. So yes, the ‘big’ in BigQuery just means it works at those scales.