Answer and Explanation:
The bizarre thing that happens to Macbeth’s chair after he got to the scene of the banquet, is that it was occupied by Banquo’s ghost. Before the time of the banquet, Macbeth had ordered the killing Banquo, which was successful; but to Macbeth’s surprise, he found Banquo’s ghost seated on his seat which was amongst other seats that were occupied by guests.
The presence of Banquo’s ghost at the banquet could symbolize that Banquo’s descendants would take over the throne, as predicted by three witches .