There is nothing to indicate that the turning of tables was done violently. It could have been done calmly.

Implying that someone is a robber is not an act of violence.

If I am a chef, holding a knife, does that mean that I am threatening or attacking people?

Jesus continued to teach in the Temple, which couldn't have been possible if he had been violent.

If he was violent, he would have been arrested then and there, which didn't happen.