Green’s Dictionary of Slang

(US) a blunderer.

1927		M. West Drag (1997) Act II: Why you big Swede. You’d take it through a funnel if anybody would give it to you.
1930		E.H. Lavine Third Degree (1931) 182: ‘Who is a big Swede, you dirty black-guard?’ he demanded.
1932		J.L. Kuethe ‘Johns Hopkins Jargon’ in AS VII:5 337: Swede—a stupid or clumsy person (signifies general disapproval).
1945		R.I. McDavid Jr ‘International Slurs’ in AS XX:2 132: What’s dumber than a dumb Irishman? A smart Swede.
1979		Maledicta III:2 173: Swede n 1: Blunderer.
1989		H. Rawson Dict. of Invective (1991) 378: Swede. A blunderer, a dope; sometimes, for emphasis, a big dumb Swede.