The product is flimsy and badly designed. We had bought the 78" (large size) dining table and had to return it due to quality issues. 
Here are two reasons why you shouldn't buy this product:
1. The steel/iron frames are very flimsy. It gets easily bent, twisted, and buckled
2. The flat surface of the table is made by assembling 5 planks in tandem. The longer two planks, even if it is slightly bent can never align to become a flat surface because there is no screw mechanism provided to hold it tight. Check out the attached image. This happens with 78" table for sure.

Thanks to Wayfair for understanding the concerns and accepting a return. 
Overall, not a great product, and will not recommend buying it.