Volume of table $=$ volume of tabletop $+$ $2$ $⨯$ volume of each support

Dimensions of tabletop are $4$ in., $28$ in. and $18$ in.
Dimensions of each support are $14$ in., $27$ in. and $5$ in.

Volume of cuboid $=$ length $⨯$ width $⨯$ height

Sum of volumes $=$ $4⨯28⨯18$ cubic inches $+$ $2⨯14⨯27⨯5$ cubic inches

Volume of table $=$ $2016+3780$ cubic inches $=$ $5796$ cubic inches