  In this paper we show that a complete and non-compact surface immersed in the
Euclidean space with quadratic extrinsic area growth has finite total curvature
provided the surface has tamed second fundamental form and admits total
curvature. In such a case we obtain as well a generalized Chern-Osserman
inequality. In the particular case of a surface of nonnegative curvature, we
prove that the surface is diffeomorphic to the Euclidean plane if the surface
has tamed second fundamental form, and that the surface is isometric to the
Euclidean plane if the surface has strongly tamed second fundamental form. In
the last part of the paper we characterize the fundamental tone of any
submanifold of tamed second fundamental form immersed in an ambient space with
a pole and quadratic decay of the radial sectional curvatures.
