Bin and broom next to our table

At 8:30pm tonight, while still eating our food. A lady looked at us funny holding a broom and a bin. Paid no attention her,only to realised few minutes later that she had left those 2 next to our table. 2 other waiters went past avoiding the bin. I had to ask them about it before they moved it. At 8:50 same lady sang "asambeni" as she went past us. I'm still in shock and disbelief