Enable auto-propagation SDL Studio
Go to
File→
Options, expand the
Editor tree, go to
Auto-propagation and check
Enable Auto-propagation and
Confirm segment after auto-propagating an exact match.
This will automatically fill up the translation in repetitions after you have translated the segment once. If you need to make corrections in these repetitive strings, on the same panel check
Auto-propagate exact matches to confirmed segments (if you keep this option ticked while translating there is a risk of overwriting segments that contain tags).
http://producthelp.sdl.com/sdl%20trados%20studio/client_en/Setting_Preferences/AutoPropagation/Pref_Enable_Auto-propagation.htm