Can cells be fully cleared? Clearing numeric columns leaves "dots" behind

[#1]

I made a copy of a table because I want to reuse the same column headers and types that I had already set up. But I want to clear the contents. Clearing the contents doesn't seem to really work. The left-most "column" which numbers all the rows still has all the numbers filled in from before, and the numeric columns still have dots in the cells instead of empty cells. Like this:

This is annoying because when I was making the first table, there were a lot of repeating nominal data. For example, x number of data points all have the same label. I would paste in the numbers then fill in the top row associated with that and right click > Fill > Fill to end of table. Now if I do the same thing, the end of table is all the way at the bottom where all those dots end, NOT where it should end, which is wherever the last row of my freshly pasted numeric data is. 

Why can't the cells be completely cleared? 

My JMP version is 16.0.0. On Windows. 

PS: only interested in working in the GUI for now. 

[#2 · Accepted solution]

Likely what you did is delete the cells rather than the rows -- if you select rows and press the <DELETE> key then it will do what you want.

The easiest way that I find to do this is if I have a mixed selection like this:

Then click the null-space in the upper-right portion of the first cell (see the red circle here) to deselect the columns -- this changes the selection from a selection of CELLS to a selection of ROWS.  Pressing delete now will delete the rows entirely instead of clearing the cells.

after pressing delete:

[#3 · Accepted solution]

Yes.

A region of cells with both columns and rows selected

Clicking at A will deselect columns. Clicking at B will deselect rows. You can right click at B and select all rows.

To delete columns, make sure no rows are selected. To delete rows, make sure no columns are selected.

The dots represent missing values.