How Plan Explorer Group Operators in Query Columns Tab
At first, it looks like you've modified XML, because the query does not exactly match the plan.

At second, format your query like this 

SELECT o2.Column1, 
       o2.Column2, 
       o1.Column3, 
       o1.Column4, 
       o1.Column5 
  FROM Object1 as o1, 
       Object2 as o2, 
       Object3 as o3 
 WHERE o1.Column3 = o3.Column6 
   AND o2.Column1 = o3.Column7 
   AND o3.Column8 between ? and ?
   and o3.Column7 &lt; ?


At third, instead of having separate indexes on Column7 and Column8 (green and red seeks) you better create one index on Column7 + Column8 (green first) and have included Column6. That will help you to avoid Red Scan.

At fourth, (optional) you can create index on o1.Column3 with included columns o1.Column3, o1.Column4, o1.Column5