To fill empty cells in a table with values you can use the filter for "Fill Empty Cells with", this can be found under the Refine Cell Values option.
Once selected there are a few options that can be used to determine the value of the cell in the column of your choosing. These are as follows:
Set to value of previous row
Set to value of next row
Set to static value
The default option is to set to value of previous row, so if row 1 contains a 2, and row 2 is empty, that would become a 2. This can be shown in the example below
With the option to Set to value of next row this would do the opposite and take the value from the row below, so in the example below you can see that the rows are filled in the opposite where the 4 from row 4 fills all empty cells above
The last option is to choose a static value - this is a manually typed in value that will fill any empty cells found in that column