Translation:I eat a lot.
Yes, "I" is usually how it's interpreted - though it could refer to one of the other pronouns if the intended subject is already implied by the context.
The use of ね doesn't necessarily imply anything about who the subject of the sentence is - but it would be weird to say something like "I eat a lot, don't I?" about yourself.
just a thought:
this is under the 'Position' topic, which deals with left-right, bottom-top and so on. What does eating - no matter whether a lot or a little - have to do with position of anything?
Could that be that the eating is sort of 'placing a food in the upper opening of the body'? Or perhaps that the whole process is conducted in some undetermined (and not mentioned in the sentence) position? ;)
It's incorrect on the English end... Check this site: https://dictionary.cambridge.org/amp/british-grammar/quantifiers/much-many-a-lot-of-lots-of-quantifiers
This sentence is assuming "I eat a lot (of food)" where food is a singular uncountable noun, like "money" in their example sentence "That's a lot of money"
the subject is not stated so it could be he eats a lot, she eats a lot, they eat a lot. The phrase is not stated for present time but for future "Masu" , if it's present time then it would be "Taberu" - "Takusan Taberu". In simple words, it's confusing and is wrong. DUOLINGO FIX THIS!
Technically speaking, I agree. "A lot" to mean "much/many" is similar to the use of "a bunch." I'm pretty sure it used to be a measurement at one point (i.e., "a bunch of grapes") but became more vague in casual English over time, understood to mean "many/much" as a sort of colloquialism. It's adjacent to hyperbole at this point, I'd say. ("I've told you a million times"-esque, where this phrase actually just means that you've told the person several times and are tired of telling that person the information in question.)
"Much" is mainly used formally in writing and is typically used with negative statements and questions, with the positive exceptions being if it begins a sentence and if preceded by words like "so/too/as/very". It sounds extremely unnatural in a positive on its own like that.