"This table is bigger."
Translation:Dieser Tisch ist größer.
Without context, it could be either. Note that a Tabelle is a table in the sense of information presented in rows and columns, while a Tisch is a piece of furniture with a flat top surface.
I wrote 'Dieser Tisch ist grosser' (I did not not umlaut the o) and Duo accepted it. Was Duo too lenient on me?
Me too. It gave the umlaut as an alternative answer, but it is wrong to leave it out isn't it?
Yes Duo was too lenient because it does not mark you wrong for missing an accent (but it should) and it accepted "ss" for ß in case you couldn't type ß, but it should have been größer