To find the area of the trapezoid-shaped tabletop, we can use the formula for the area of a trapezoid:
\[ \text{Area} = \frac{1}{2} \times (b_1 + b_2) \times h \]
where:
- \( b_1 \) is the length of the shorter base,
- \( b_2 \) is the length of the longer base,
- \( h \) is the height of the trapezoid.
From the information given:
- \( b_1 = 36 \) (shorter base)
- \( b_2 = 48 \) (longer base)
- \( h = 18 \) (height)
Now we can substitute these values into the formula:
\[ \text{Area} = \frac{1}{2} \times (36 + 48) \times 18 \]
Calculating the sum of the bases:
\[ 36 + 48 = 84 \]
Now substituting this back into the area formula:
\[ \text{Area} = \frac{1}{2} \times 84 \times 18 \]
Calculating \( \frac{1}{2} \times 84 \):
\[ \frac{1}{2} \times 84 = 42 \]
Now multiply by the height:
\[ \text{Area} = 42 \times 18 \]
Calculating \( 42 \times 18 \):
\[ 42 \times 18 = 756 \]
Thus, the area of the trapezoid-shaped tabletop is:
\[ \boxed{756} \text{ square inches} \]