You are asking about tax rates in dozens of entites of various levels of independence accross a timespan of centuries. As such a simple generic answer simply can't be given. I can break you down tax rates in 15. century Kingdom of Hungary which is what I am familiar with. Many of the taxes listed span back to the kingdoms founding and were present in other countries as well, some were unique. And before I dwelve into I have to note that taxes weren't supposed to be paid only money only. In fact paying tax through labour and through giving up produce was much more common practice. Also taxes usually weren't individual taxes but instead were collected by household which roughly equaled an extended family This was determined in a variety of ways about what exactly consituted one household or a family, such as per chimney or per gate, but at the end of the road judgment was made by the landlord's appointed collector. As you can imagine people were quite creative even back then regarding tax evasion which is why the criteria was occasionally changed, the infamous example being the late modern English window tax which led to some poor walling up their windows, but in Hungary too when gate-tax was the measure peasents just demolished gates and used one leading to many households sometimes.

The two quintessential tax form was the nona aka "the ninth", and the tithe, also called decima or tenth, each being a 10% of harvested produce. Of this the tithe has the longest history spanning back to early Christian ages, and were collected in practically all countries from the point of their conversion. The nona was collected from the 14. century and was to be given to their respective landlord by each peasent household in form of produce. However this was typically done together with collecting the tithe for sake of easier administration and work (and in turn the landlord had to pay an appropiate share to the local church body). There were designated places to give over your tax-goods, and in many Hungarian villages they are still preserved as "decima-houses", "decima-caverns" (think paying wine) and so on.

A regal tax pretty always paid in coin were plot/house taxes. The size of this was quite exact: 18 denarius for most of the 14-15. century (100 denarius = 1 florin, with most peasent household having a total of one to few florin worth annual income). Another regal tax was the subsidium which wasn't a regular payment, but could be imposed in wartime. Depending on how much land the peasent family worked on, one to three florins annually. The other large class of taxes were theose to be paid in labour, variously called robot or servitum, and it entailed unpaid work on the landlords lands, which was basically the rental fee of the land peasents cultivated for their own living (as they themselves did not own the land they worked on). This was few days a year from the XI. up to the XVI. century, then a day per month after, but by the XVII. century a day per week!

Compulsory "gifts" called census and munera were also a thing, and yes these were intended to be gifts given to the landlord as form of goodwill. Three times a year until 1514, then monthly after. Hard to quantify, mainly paid in form of smaller livestock like pigs or chicken. Then there were many, many smaller items. Milling tax for milling your grain, all sorts of customs taxes and and a mind-boggling number of local taxes depending on a regions product speciality, but I'll disregard these for now.

So of course everyone wants a number, but as you can see even if I focus on a specific century for a specific kingdom its not so easy to add numbers up due to the nature of these taxes. But I'll make an attempt: Tithe + nona = 20%, plot tax = ~5-20%, robot = few %, munera = few %. So per household a rough average would be 40-50%, with poorer hhs. paying relatively more due to the plot taxes's fixed nature. But if the subsidium was collected (some games do simulate this through war tax), then the % can jump up quite a lot, up to and over 90% !

Sources I used:

Hungarian Ethnographic Lexicon

History of money in Hungary, Márton Gyöngyössy

Financial and economic policy in the Kingdom of Hungary, Bálint Hómann

Life of Serfs, György Domanovszky