Please consider increasing both the starting, and end size of each inventory page. A game like this doesn’t need to have an obtuse and annoying to use inventory system, especially as you pick up far more items than other games in this genre.
I’d also suggest adding more category pages for items to allow easier navigation, and again more space for players to store their items and less need to discard potentially useful items. I suggest splitting the weapons and the armour into their own pages, as well as splitting the resources into more groups as it’s confusing having food items sharing the page with ore etc.
I know you want the player to feel a sense of progression when handing in items to increase inventory, so perhaps for each upgrade of your inventory it’s a bigger upgrade. Maybe the first gives you +4, the next +6, then +8 +10 etc. this would make inventory management important in the early game, while also preventing tedium in the mid and late game