See Truncated Text in Report Columns

To fit multiple columns on a small mobile screen, parts of the content of a field (the middle words of a text field or the trailing digits for a numeric field) may be dropped out. Salesforce1 users can now tap the field to see the full text in a pop-up, then tap the pop-up to go to the record.
Reports available in: All editions except

Tap a field to see text that's been truncated to fit in a table column.
  1. Tap an abbreviated table cell to see it spelled out in full.
  2. Tap Go to Record to see the underlying data.