Ilya
The problem still persist. I will explain you all the tests I've done based on your last response.
Since it works for you but not for me, I've just thought the problem could be:
-either the lenght of values inserted on column "Details"
-or the format I chose for column "Details"; since I defined it as string but used the following structure inside: [{},{}]
No matter which filter I enclude in the curl query, the filter do not apply but the whole list of registers are given as response; also a warning message is shown:
curl: (3) [globbing] unmatched close brace/bracket in column X
So I first created a new table (called ai2_events) from scratch with the same structure, three records and the same content on column "Details": [{},{}]. I send the query to the new table, but still getting back all records in the response, and also the warning.
Then I removed colum Details and created a new one with same name, but selecting Array as format. On curl response I do not get warning, but still all the records are received.
I finally created a new table (called ai3_events) with column "Details" format set to Array and with an empty value in all my three records.
I run a new curl test, but still the same problem... !?
curl -X GET -H "X-Appery-Database-Id: 54133d17e4b055c018db7f29" -G --data-urlencode 'where={"school_id": "2"}' https://api.appery.io/rest/1/db/colle...
This request should retreive just one record, right? Well, it gets again the three of them 
curl: (3) [globbing] unmatched close brace/bracket in column 2
[{"id":"55696d3ce4b0d4930d289bc2","Month":"2015-05-01 00:00:00.000","createdAt
":"2015-05-30 07:56:44.773","updatedAt":"2015-05-30 07:57:32.617","Type":"Menu"
,"school_id":"1"},{"id":"55696d72e4b0d4930d289bc4","Month":"2015-06-01 00:00:00
.000","createdAt":"2015-05-30 07:57:38.752","updatedAt":"2015-05-30 07:57:45.0
01","Type":"Menu","school_id":"1"},{"id":"55696d81e4b0d4930d289bc5","Month":"20
15-06-01 00:00:00.000","createdAt":"2015-05-30 07:57:53.045","_updatedAt":"2015
-05-30 07:57:59.880","Type":"Menu","school_id":"2"}]
Suggestions are welcome. Thank you in advance!
Javier