Inserting a Horizontal Space Character
It's possible to this easily outside of a table cell. To do this, 


insert a tab between the two text, and then 
add a tab mark on the ruler above.
Move the tab mark to adjust the tab width.


Doing this inside a table cell is difficult because pressing the tab key automatically advance the cursor to the next table cell. What I suggest is 


create the tab outside the table cell, then
paste it inside the table cell, then 
adjust the tab width.


I've snapshot to illustrate what I mean. Hope it helps.