Do you mean in a table?

It's just that in a blank document, if the space bar did as you described, you would only ever be typing one word lines, eg;

type
a
word
and
press
the
space
bar
and
get
a
new
line.

(You won't believe how difficult it was to do that, Happy )

But, if you are in a table cell and have reached the end of the cell, then pressing space will automatically move to the next line down in that cell.

But if you want to move from one cell to the next cell, use the TAB key, (the one above Caps Lock).

Or did I not understand the problem correctly?

Mark