The suffix "eg" can be used to show a greater size in nouns. For example "libro" (a book) versus "librego" (a tome). But it's not only for size. You can use it on adjectives, for example "bela" (beautiful) versus "belega" (gorgeous). It can be used in adverbs for example, "malami" (to hate) versus "malamegi" (to loathe).
The suffix can by used by itself as a noun, adjective, or adverb, but the meaning is a bit ambiguous. "Ego" (or "egeco") could mean vastness, height, width, depth, or greatness. "Ega viro" could mean a tall man, a broad-shouldered man, a fat man, or a great man. "Ege" would add emphasis to an adjective or verb, like "ege bela" (really beautiful) or "ege malami" ("to really hate" or "to hate a lot").