"Mama Pads" and "Mama Cloth" are 2 of many other names for cloth menstrual pads. Others include "Moon Rags", "Moon Pads", "Rags", "Cloth San-Pro", "Mama Fluff".
There is a bit of a love/hate relationship with the term and the way many pad businesses (particularly WAHM) are targetting customers and displaying their products. You will often find cloth pads listed on their websites/online stores under headings such as "Mama items", "Diaper accessories", "For Mum" etc. usually relating cloth pad use with being a mother.
Some women (particularly those who are nulliparous) find these mother-specific terms to be exclusionary and almost offensive. Some women simply don't make the connection between cloth pads and being a mother, so do not think to look under a "for mum" or other such heading to find cloth pads, or assume that any cloth pads listed there would be for post-partum bleeding (or some other mother-related thing they do not know of), not for regular menstrual use. It is in fact more common to see long and highly absorbent cloth pads being marketed as "Post Partum Pads", designed to attract expectant mothers, than to see them marketed as "night" or "heavy flow" Pads.
Presumably this link with cloth pads and being a mother relates to the fact that many women discover cloth pads as a follow on from cloth nappies/diapers they use on their children, or through use of the term "mama pads" by mothers who use them. So for many women the two are connected. However the predominance of the term continues to build up its association with being a mother, causing more women to refer to them as "mama pads" and so the cycle continues.
Another reason for "Mama Pad" is that using the term "Cloth Pad" can be ambiguous to some people. Seeing or hearing those 2 words may not instantly mean "cloth menstrual pad" to everyone. If you type "cloth pad" into a search engine, ebay or other such place, you'll get some idea of the fact that the term can be used for many different items. Particularly if it is in use around cloth nappies/diapers - where it could be mistaken to be a part or accessory for use in those. Using the word "mama" helps target it to be something that a mother would need, rather than the need of a child….. Thinking like this - mothers menstruate, therefore a "mama pad" is a menstrual pad. You can see how a connection can be made in this fashion.
There is also the possibility that connecting cloth pads with the term "Mama" etc. rather than "Menstrual" is thought to help customers see them in a more positive way. Where in society the word "Menstrual" usually conjures up negative emotions, relating something to a mother could instead be seen as being something women might find less confronting or more appealing. Where some women embrace the word "Menstrual" or see nothing wrong with it, for many women this word is one best uttered in hushed voices if it is spoken of at all. Think of the myriad of terms used to avoid actually mentioning Menstruation ("Aunt Flow", "on the Rag", "Crimson Tide", "Monthly Visitor" and so on.)
The term isn't intended to be offensive or to convey any type of exclusion against those women who aren't mothers, it is simply another name for cloth pads, however wide spread and incorrectly targeted it may be.