Do we need a table plan?

That sounds lovely and I think poems instead of name cards is really personalised and informal. I think it would be really different.
I hope you have a wonderful wedding. Me and my fiancé are getting married in Gretna Hall on Halloween next year! X

We went to a wedding recently with no seating plan and it was a bit confusing to be honest, as guests weren't sure where they should sit to leave room in the right place for the bride and groom and their parents or who they would want to sit next to so it kind of had the opposite effect to the relaxed vibe at first. I'd suggest reserving one of the round tables to be a top table for the bridal party as it actually gives people more comfort that they aren't sitting in the "wrong" place - even if you do move about later.

I think it’s best to do a seating plan. Realistically, there will need to be a certain number of people on each table, and you don’t want to end up with 10 people squeezed on to one table and six on another feeling like other people don’t want to sit with them. Do the seating plan, but encourage everyone to get up and chat between courses, if that’s what you want.

Just to add to the above. I do think its less confusing for guests when there is a seating plan, although I love the idea of having everyone mingle, people will be confused and you want to ensure you can sit with your parents/bridal party. Also if you are having a sit down meal rather than a buffet, a seating plan will show the servers who the vegetarians/vegans are and who has any allergies. So it will be much easier for them to track what plates are going to what table.

The problem with having no seating plan is that waiting staff won't know who to deliver what meal to, and also, if you have any guests who have come alone, they may end up being excluded. I've been to a 'no plan' wedding where I ended up sitting in isolation at one end of a table while the rest of the table (who all knew each other really well) completely ignored me.

If everyone is having the same meal (or picking up their plates themselves) and if everyone knows each other, then you can get away with it.

A happy compromise might be to assign people tables but let them choose where they sit on those tables.

Thanks for all your replies. It’s a buffet meal for an evening only do, so we want it to be relaxed, but I see what you’re all saying too. I think we will just do a plan that tells people what table but leave the seat choice to them.

Thanks for your help xx