I can think of a few ways to give you something like this, depending on exactly what you need.
Approach number one:
Use the modeling type of Ordinal for your numeric column (if they are truly continuous, you may have 100 rows, each with frequency one -- which I assume is not what you want).
Make a distribution of that numeric column.
The Frequencies report will give you a list of each level, along with a count for each level. Selecting a row of that report will select the corresponding rows in the table.
If you must have the frequencies in a data table, you can use Tables > Summary. Specify your numeric column as the Group variable and that is it. You will get a new table that has the numeric values along with the frequencies of each number. Selecting a row in the new table will actually highlight the rows in the original table, too.
Finally, if your numeric column is continuous and you wanted to make a histogram and save the frequency of each histogram bar back to the data table (rather than counting the frequency of each value) that is more involved. First, make your histogram using Distribution. From the red popup choose to Save Level Numbers. Use Table > Summary and choose the new Level column as the Group column. Now join that new table with the original table, matching by the Level column. Keep in mind that this assumes you are using all of the standard bins that JMP determines. The approach will work if you create a custom bin width, but re-creating the new histogram using your custom bin widths will not be automatic.
Dan Obermiller