I guess there's not much we can do but ride this out? Audrey starts out her meals on her chair but after just a couple of minutes she pushes her plate purposefully towards DH or me, and says "Sit daddy's lap" or "Sit mummy's lap". After that there is no getting her back in her chair, she won't eat anything else unless she is sitting on a lap. Sweet that she likes being so close to us but it does make it trickier to eat our own meals, plus this is totally a habit now and just won't sit on her chair for a meal.
Her chair is a high chair, but the front bar piece (which should restrain a kid) is taken off because she was climbing in and out of it and it was way more dangerous than removing the bar and having an 'open' chair that she can get into and out of with ease. So there's no physical barrier to her getting up and down from the table (and therefore to coming round to my seat and crying and begging to sit on my lap).