Using Crowdin to translate SuiteCRM you can filter for strings and work in more than one file at a time.
You can also filter strings from any language file. This will allow you to keep consistence across files.
The strings for that file will be displayed to translate. If you want to list all strings, from all files and in the same page, go to the next step.
Step 4 - You can also filter "All strings" by several options
With "Custom filter" option you can also filter for an user or strings that got translations after you approved it:
Enter Crowdin to translate SuiteCRM into your language