There are many mountains in the world that have a "tabletop" structure. I will focus on two candidates for the title of the world's largest table mountain.
Mount Roraima : The English explorer Sir Walter Raleigh first described this mountain during his expedition to the area in 1596. It is located at the tripoint of Venezuela, Brazil, and Guyana. The summit area is defended on all sides by 400-meter-high cliffs. Its total height is 2,810 meters, and its summit area is 31 square kilometers. In short, a massive, flat-topped mountain.
Here is another view from above:
The second candidate is Table Mountain , Cape Town, South Africa: The tabletop lies 1,086 meters above sea level. The length of the "table" is approximately 3 kilometers. The image below is the front view as seen from the harbor area of Cape Town.
Table Mountain is certainly not as high as Mount Roraima, and as far as I can tell from my visits, its "flat summit" is no larger than 31 square kilometers. This makes Mount Roraima the largest table mountain.
But it's clear that anyone can easily take the cable car to the top of Table Mountain, or you can hike up, which is what I did. Here's part of the Smuts Trail, which starts in Kirstenbosch Gardens, that I took:
It takes about 1.5-2 hours to reach the summit.
In contrast, climbing to the summit of Roraima requires serious climbing with professionals.
The view from the summit of Table Mountain is spectacular. Here is a view from the top of Table Mountain, with Cape Point in the distance. Note the causeway at the summit of Table Mountain. This picture was taken near the Maclear Lighthouse, the highest point of Table Mountain.
Our hike began in Kirstenbosch Gardens, following the Smuts Trail. Here's a view from above of Cape Town and Signal Hill:
And finally, a view of Camps Bay on the Atlantic side:
In summary, Roraima is the largest flat-topped mountain in the world, measured by the height and extent of its tabletop, but Table Mountain, while the second largest and second highest mountain in the world, can be easily experienced by everyone, either by hiking or taking the cable car to the summit!