src/vs/workbench/contrib/notebook/browser/contrib/navigation/arrow.ts/getPageSize
function getPageSize(context: INotebookCellActionContext) {
	const editor = context.notebookEditor;
	const layoutInfo = editor._getViewModel().layoutInfo;
	const lineHeight = layoutInfo?.fontInfo.lineHeight || 17;
	return Math.max(1, Math.floor((layoutInfo?.height || 0) / lineHeight) - 2);
}