Put the names of the planets in column A, the relative gravity data in column B, and the formula for computing your weight in column C. In a separate cell, say D2, enter your weight on Earth. Use the formula, =B2*$D$2, in cell C2 to compute your weight on the planet in row 2. Then, since you are using absolute addressing, you can simply use Fill Down to copy this formula into the rest of the cells in this column.
The gravity data in this table is from Bill Arnett's web site The Nine Planets.