This question already has an answer here:
- Merging cells in Google Docs 1 answer
I want merge (remove the separation lines between them) three cells horizontally in google doc.
This question has been asked before and already has an answer. If those answers do not fully address your question, please ask a new question.
select all three (shift click will work) then click the "Merge Cells" button on the top tool bar. Only the data in the left most cell will be kept.