a palavra tem mais de um significado?

Lot can mean several things:

“a lot” – Something that you do very often, or that you do very much of.
“lot” – A section of ground that you put a house or building on.
“lot” – A grouping of things, sometimes sold at auction.

In this case, “a lot” is a phrase and has the first meaning. If you “read a lot” then you read very often.