Question

a large highland area of flat land separated from the surrounding land by steep slopes, formed from lava flows, upward folding, or erosion

Answer 1

The geographic feature you are describing is typically known as a "mesa." A mesa is a landform characterized by a flat-topped area that has been raised above the surrounding landscape, often with steep sides. Mesas can be formed through volcanic activity (such as lava flows), tectonic processes (such as upward folding), or erosion that has removed softer material around a harder rock layer, leaving the flat top intact.