Question

The greatest of hall-buildings; heorot he named who wide-reaching word-sway wielded Ming earlmen. His promise he brake not, rings he lavished, Treasure at banquet. Towered the hall up high and horn-crested, huge between antlers

Answer 1

The very characteristic depicted in the said lines is what Heorot was usually referred to -- "the foremost of halls under heaven".

Thus, Heorot was elegant, extravagant, filled up and spaciously massive.