rowHeight

The height DataTable gives a row when it is not told one: enough for a single line of body text at density's padding.

Rows being a uniform, known height is what lets the table cull the columns that scroll out of sight — a row that sizes to its content changes height when the tall cell is the culled one, so DataTable will not cull for a table whose rowHeight is null.

This assumes the default bodyCell style. A larger font, two lines of text, or a cellContent holding a chip or an avatar needs a height of its own — pass one to DataTable rather than deriving it from here.