Yes, 255 MB is too big. If they’re image textures, the images themselves are external assets and won’t be included in the file without explicitly packing them in. If they’re not packed, something else in the file takes so much space. Maybe you have some images packed in, hdri files are big for example, and the rest is geometry.
The reports you’re showing are part of info editor at the top. Drag the top header back up. It’s actually part of the info editor and rest of it is usually hidden.
You seem to have at least renamed the scene. If you have multiple scenes, check scene properties -> scene: background if there’s another scene set there. If there is, that’s where you might have another object that appears in this one.
Scene properties in #3 http://getblended.org/screens/propertiesbuttons.jpg
It’s possible that while preparing an example .blend for upload you come across the culprit. Could delete most of it, maybe all of it, but it’s important that you’re still able to see the problem with the file you upload. But if you don’t care what causes it, could start a new file and file -> append, browse to your saved file and open it, and import objects or the whole scene from that and see if the problem goes away.