ah I see
The end goal is controlling the height and width and other style properties of a dataview table?
I don’t think you can put it in an iframe the way you’ve attempted.
However, dataview tables are directly selectable with CSS. So, you can create a CSS snippet targeting all dataview tables and style them however you want. Or, if you only want to style dataview tables on a certain page, you can use the cssclass YAML attribute to select for those.