Dad has recently been barricading the front door, and the door to his bedroom. My Mom, who has end stage Alzheimer's is in that room. We have a live-in aid. I fear for their safety since it takes longer to get out of the house, if necessary. Is there something that can be done? Dad is unreasonable. All that he will do is shout. He has dementia too.
Maybe try zip ties? Zip tie the legs of the chairs either to eachother or to the table. A place like Home Depot or Lowes have zip ties in different lengths or if you need really long ones, zip tie the ties to make a longer tie and then tie that to another chair or the table.
Good luck, Parruska